FSE

Furry search engine

formerly SoFurry search engine

This story was a bit of fun between myself, :iconAtlas86: and :iconLost-Soul:

Big thanks to https://www.furaffinity.net/user/synxthelynx for proofreading the story!

***

Sabrina wilted in her small office chair as she read over the pile of papers on her desk for what had to be the sixth time in the last half hour. No matter how hard she scrutinised the exam results sitting in front of her, or how often she recounted the scores, it never changed the result.

Throughout the dozens of questions that compromised the test, the number of red crosses and notations was depressingly high. For all she had studied and tried to wrap her head around the topic, Potions class continued to trip her up. She didn't believe she had worked any less than the other students in her class, yet the final results laid bare in front of her told the truth of the matter. She didn't even score the bare minimum for a passing grade.

To make things worse, Potions was a mandatory, core class for her degree in magical forensics. Fail it, and she might even fail the course altogether. It meant another whole year in the magical academy at worst, and there was no guarantee another year of study would even net her a passing grade. She had no faith that her grade would simply improve with time if all her effort prior to this still resulted in such a poor mark.

Sighing, Sabrina rubbed at her tired eyes and brushed a stray lock of her long, black hair back behind her ear as she started to think over what options she had left. There were very few, she considered idly. There were no mistakes with the marking and retaking the exam was now out of the question. In the end, there was only one option she could think of, and that was to go and directly plead with her Potions teacher for help.

With a nervous stroke over her hair to straighten out some errant strands, Sabrina stood up and collected her papers, making sure to smooth out her school robe before leaving her lodging and locking the door behind her. The walk to her teacher's office seemed to drag on before her as she travelled down numerous corridors, deep into the heart of the academy. Her nervousness grew as she approached the large, wooden door of her Potions teacher, her eyes glancing over the metal placard with the name 'Arvus' engraved into the steel.

She might not have felt so nervous if her teacher was human, but Arvus was a centaur, and one of the largest of his kind Sabrina had ever seen. There was just something that was instinctively intimidating about the half-horse, half-human beast, and after taking a moment to steady her nerves, she knocked several times on the door.

A moment later a deep, bassy voice sounded from behind the door.

“Come on in."

Turning the handle, Sabrina opened the door and stepped inside, closing it over behind her even as she took in the details of the office in front of her. It was a fairly neat room, with several shelves densely packed with books about potions and other magical subjects, some modern and some with old, fading titles. She suspected some of them might even be limited editions or considered antiques from centuries past.

Aside from those, and several official-looking filing cabinets, the main centrepiece of the office was a large, dark mahogany desk. Behind this stood a large centaur, the horse's half of his body a luxurious, soft looking brown, though most of the rest of him was hidden by the similarly-coloured desk. Sabrina could see the draping wizards robe the centaur normally wore in public hanging on a stand to the side; normally his species didn't concern themselves with nudity and modesty as humans did, so when teaching in class or moving about the university he normally wore the garb to cover himself modestly.

Arvus' torso was a light tan that seemed to accentuate the well muscled abdomen and arms that accompanied the rest of his powerful equine body. She noticed the bright blue eyes staring down at her sternly, and she swallowed nervously in his presence.

“Professor?" she asked, approaching the front of the desk even as the centaur attempted to burn a hole through her with his stare. “Can I talk to you for a moment?"

“Is this about your grade, Sabrina? What could you possibly have for me this time? Did another student's raven steal your study notes for its nest?" he asked, and she couldn't help but flinch. He could read her like a book, not that she'd ever come to him before with anything except poor excuses. She'd barely gotten away with the old 'frog jumped back out of the cauldron when she was checking her book' excuse last time, and on a written exam like this there were no absurd situations she could hide behind.

“Please, Professor," she grumbled, weakly falling to her knees before him. She'd never noticed just how huge her bestial professor was, with his firm gaze still visible even when everything below his abs was hidden by the edge of the desk. “I can't fail this class. I need your help."

Arvus released a deep sigh, and for the first time Sabrina saw his stern facade fall away. Instead, he put his hand to his forehead and shook his head, looking to her in utter disappointment.

“Sabrina, if you needed additional support for my class, you should have come to me with this concern months ago," He explained, causing her to bow her head. She had been nervous going into Arvus' office before, even scared. She'd never really felt ashamed of it, though, not like she felt now. “As it stands, it's too late for you to get tutoring, and frankly there's just not enough time left in the semester for you to make back the ground you've lost."

“So, I'm going to fail?" she asked, her lower lip curling and just beginning to waiver. “I need to pass this class. If I don't, my career will be over before it's even started. There's really nothing you can do?"

Arvus turned away from her for a moment, and from her place on the floor she watched his tail flick towards her, almost as if he were waving her away. “There's nothing I can do for students who won't at least put in the effort," he replied with an air of finality.

It was as if he had taken his marking pen and written a big, fat zero right on her forehead. Her heart sank; she felt like her dream was over. Then it dawned on her, like a ray of light shining down in her from the centaur's looming rump. All she had to do was put in the effort. Even if it wasn't effort into her studies, there were plenty of other things she could do.

"I will put in the effort," Sabrina muttered to herself, causing Arvus to turn back towards her with his brow slightly cocked.

"What was that?" he asked, and Sabrina was gifted the sight of seeing her stoic teacher taken aback by the determination in her eyes.

"I'll do whatever you ask!" she exclaimed and shot to her feet with her palms slamming down onto the edge of the desk.

"Whatever I ask?" he repeated curiously.

"I'll wash the chalkboards in the lecture hall. I'll mop the floors in the lab," she added emphatically. "I'll feed the crickets, and feed the crickets to the frogs, and feed the frogs to the snakes! Increase my grade, and I'll do all your chores for the rest of the semester. I'll do anything. Please, Professor!"

Arvus stared at the young woman for a moment, his eyes staring her up and down as if taking her all in for the first time. Perhaps he was simply seeing her in a new light, showing all of this determination and desire to succeed. Her method may have been slightly unorthodox, but her message was clear. It had been a while since he'd had a student come into his office showing such determination, especially one with a body like hers.

“Alright. Come with me," he replied, and she swore the centaur cracked a bit of a smirk before turning away and trotting for the closet door at the back of the office. Either way, her eyes lit up, and she nearly vaulted his enormous mahogany desk in excitement as she fell in-step behind him. If it would get her through this class, then a couple months of any chore would be worth it.

As he stopped before the closet, the burly centaur looked back at his student, his expression a mixture of stern consideration and possibility. She barely noticed the wand in his hand before it was too late.

A single word escaped his lips and she was immediately bound and magically gagged. Her hands pinned behind her back, and her lips closed over as she realised her teacher had cast magic upon her. It was not rough, yet it had come as a significant shock.

"Apologies, Sabrina," he told her firmly, "I couldn't risk having you make a commotion should you not accept my offer." He placed his wand down on the cabinet nearby, watching as she struggled briefly against the charm before looking up at him with angry eyes.

"Relax, my dear," he added with a dismissive wave of his hand, "I shall release the charm once you have heard my conditions for raising your grade. You see, what I am going to propose is not exactly... legal." She stopped resisting for a moment, ears twitching at his words. He turned back away from her, reaching to the closet and opening the door wide.

As the wooden closet creaked open, she looked around his large body to see what her teacher was keeping inside. Her first thought was that he likely had some store of illicit, experimental potions, and that she was to be his test subject in exchange for a grade. Yet, as she glanced inside, all she could see was a mass of what looked like large black and brown leather straps. Her eyes widened a little as he pulled it out, clinking and thumping heavily as he hauled whatever it was out of the closet and carried it over to his desk, dumping the lot right in the middle.

He looked at her for a moment, and then retrieved his wand, pondering for a moment before looking at her.

"I'm going to relax the charm on you," he told her gruffly, "though if you speak louder than your normal voice, it will mute you once again." He flicked his wand and she felt the ability to speak flow back into her throat once more. She didn't speak immediately, however, not wanting to risk angering the centaur.

"It has been a long time since I brought this out," he explained, "it is the basis for my offer. Your grades are irreparable in Potions, my dear, but that does not mean I am not willing to forge them for you. I am well respected in this university, after all." He smirked, running his fingers over a long leather strap.

"However, respected as I may be, I am a lone centaur in a world of humans. The one thing I get so very little of out here teaching your kind is that which I am not allowed under my teaching oaths. That is to say bluntly, Sabrina, that I will guarantee you a passing grade if you surrender your body to me."

Sabrina blinked, slightly confused as her mind, still slightly shocked from having been muted and bound, took a few seconds to fully comprehend what Arvus was actually asking by that. The delayed gasp might have been comical to her if the situation wasn't so serious and happening to her.

“Professor, you mean you want to... have sex with me?" Sabrina asked quietly, her voice wavering slightly as she stared at the large, bestial form of her teacher.

Arvus seemed to find her question amusing as he lifted up some of the leather straps, the strange contraption looking surprisingly strong and sturdy despite how soft the leather looked from where she stood. “If all I wanted was as simple as... sex, I would have said so. I could have you service my cock underneath my desk while I finish my work. Or bend you over the desk to mount you."

The centaur continued arranging the straps that slowly began to take shape, though Sabrina still wasn't sure what her eyes were seeing, or her mind telling her it was as she blushed furiously at Arvus' words. “No Sabrina," Arvus continued patiently, “I want your whole body, for the whole day. You will be with me when I finish my work here. You'll stay with me when I go to my next class - Your class coincidentally - and so on, never leaving my side for the whole day. Come night time, I'll release you and you will have your passing grade."

Sabrina stared at Arvus as she tried to think up an answer. It wasn't like there hadn't been rumours or gossip around the academy about students having sex with their professors for better grades. She'd personally never thought too much about it until now, but to make her choice even more impactful, Arvus wasn't a human but a centaur. She knew enough about centaur biology to know full well they had their equine half's sexual organs, not the much smaller, human half.

Except Sabrina couldn't bring herself to reject him outright. Her whole life she had been dreaming of getting a job in magical forensics. It was both her childhood dream and her current one, with every course working towards it. Years and years of hard study and long, gruelling hours could all be worthless if she failed this one course.

“What... What exactly do you want me to do?" Sabrina asked quietly, resignation in her voice. She truly needed a passing grade, and she was willing to do anything for it, even giving her whole body to a centaur.

Arvus smirked down at her from his imposing height as with a flick, he finished straightening out the mess of leather straps and buckles. It now revealed itself to clearly be a harness of some sort.

“I'm a busy centaur, so I don't have much time to spare in indulging my needs. I haven't had anyone to satiate my need for too long with so many rules weighing me down here. This is why I'm bringing out this old friend here; it's a harness specially designed for centaurs to use with humans." The centaur lifted it up and began to step forward into it, sliding several straps up and over his back while he continued to explain. “You will be riding beneath me for the day, my cock buried inside you so I can fuck you however long I like, wherever I like."

Sabrina stared, wide eyed as Arvus finished putting on the harness and she could see he was right. There were several loose straps that she could see were meant for a human, to hold them - her - snug up against the centaur's belly, legs and arms spread. She could already see how she would be literally riding the centaur, and that every movement, every step would be like the centaur thrusting into her.

“I will relax the bindings Sabrina, then you will take off your clothes." Arvus ordered gruffly, adding, “Do remember this is your only chance to pass my class, and I only want your body for the day. Come night time, you'll walk away, a passing grade well deserved and a lonely centaur satisfied and content."

The invisible pressure holding her hands together behind her back vanished as quickly as it had arrived. She rubbed her wrists idly, as if rough shackles had just been grinding away at her flesh.

“So, you want me to get into that...thing, and go around with you all day with your..." she was halfway to actually peeking under the stallion's underbelly to see just how big he was down there, before coming to her senses and stopping herself.

“No, you were right to want to check," Arvus remarked, crossing his arms and puffing his chest to accentuate the size difference between them. “I want you to hang beneath me while my cock stretches your womb. Those are my terms. Is that so difficult to understand?"

“N-No, I suppose not," she muttered, the battle raging inside her heart. She knew she had said anything just moments before, and she really needed to pass this class, but was this really something she was willing to subject herself to? Was it worth being ruined by a centaur stallion, instead of retaking the class next year and putting the effort into studying?

“You could always say no, Sabrina. I won't hold it against you, and I'm sure you have the professionalism to not tell anyone about this. Magical bestiality isn't illegal with sentient creatures like myself, and we're not technically inside office hours anymore, meaning this is strictly personal between us. To take this to the dean would be more akin to you kink-shaming your professor than a legitimate case of blackmail." The broad centaur shook his ample hindquarters and flicked his tail, making the straps and buckles draped over his sides jingle and patter against his hide. “Besides, if you come back next year, I'll still be teaching, and you will still have time to think about the offer then, although please don't let thoughts of having sex with your professor distract you during my lectures. You have a hard enough time paying attention now."

Sabrina sighed. Arvus had her by the proverbial balls, and she knew he was right. She wouldn't be able to look at the stallion now without thinking about this moment, reconsidering her choice to not take the easy way out. Perhaps it was better for her to just suck it up and bear the humiliation of it now. Do what he asked, get her pass, and get out of his class forever.

It seemed like something out of a cheap porn movie; a student going to her teacher for better grades. Yet, as she stood before the gigantic example of a stallion, she felt anything but whimsical in her decision to sleep with him. He was truly huge, and his testicles alone were half as big as her entire head from her brief glimpse to his side. Could she really let herself have sex with a horse? From below, riding in his harness, that would be all he looked like to her.

She wasn't foolish enough to go running off to tell the dean, or to protest or beg for an alternative. He was giving her one, and she could take it or leave it.

"Do you do this to all the girls?" she huffed, and she shook his head.

"I haven't found the opportunity," he replied bluntly, "nor the right woman. What would you have me say, Sabrina? I am not shy of such things like your kind." He gestured down to the series of soft leather straps beneath his body. "I am a male with needs. If you studied enough, you would know centaurs are only male, and thus take human women as their mates. I have not had the touch of a woman for nearly a decade, and thus my need is great. That is my position. What is yours?"

She thought about it for a moment, and her future job prospects, crossing her arms. It didn't help that his human half was rather handsome, but she knew she wouldn't be much interacting with that half of him hidden under his cloak and strapped to his belly.

"Are... are you going to wear protection?" she asked finally, conceding a little, and he smirked slightly.

"Have you seen a condom that would fit a centaur?" he asked in response, " I think not. If I am to risk altering your marks in the university registry, then you will risk your eggs. Inadvertently impregnating you is not my concern. Though, it would have a certain thrill."

“You want to get me pregnant?" Sabrina asked in shock, her voice hitching up slightly at the thought. She knew if that happened it wouldn't be a normal human child but a full blooded centaur child, a foal, that would grow within her.

“I wouldn't mind it," Arvus admitted casually, “But he would be yours to raise and deal with." Arvus' eyes narrowed as he leaned down and stared at her. “Think of this as the punishment side of raising your grade. You need to and will risk pregnancy and all that comes with it, otherwise you might come to think of being fucked as a reward for scoring so poorly."

Sabrina opened her mouth, then closed it, repeating it several times like a gulping goldfish as she tried to come up with a comeback, but she couldn't. She'd not planned on looking at starting a family for at least another five or more years from now, but she was staring at the very real possibility right in front of her. It was also still the only way to continue her dream, and she had already accepted the idea of having sex with Professor Arvus to accomplish that. It wasn't certain that she would be impregnated by the centaur, or at least that was what Sabrina began to tell herself as she nodded.

“O-Okay," She agreed reluctantly.

“Good." Arvus gestured at her body and suggested, “How about you take off your clothes first? You won't be needing them in the harness ."

Sabrina blushed but had to agree. After all the talk of sex and possibly impregnating her with a foal, her getting naked seemed like a minor side note. Still somewhat nervously, she began to pull off her robe, the garment being her sole piece of clothing except for her undergarments. Plain and simple, the black underclothes covered her breasts and groin. She could feel Arvus staring at her intensely as she dropped the robe to the side then began to work on her bra, leaving her breasts bared. Sabrina then clumsily began to shuffle down her panties until she stood clear of them, her clean shaven sex bared to her professor's sharp gaze.

“Mmm," hummed Arvus in approval, looking her up and down, “For a human female, you aren't bad looking." He stated bluntly, making Sabrina wince inside. She wasn't too sure if she should be offended or pleased at such a description.

“Now that you are ready, you can get me ready," Arvus instructed her, his voice almost plain despite the note of authority the order held.

“Get you ready? What do you mean?" Sabrina asked, then watched as Arvus waved a hand down at himself, and towards his rear.

“To fit you in the harness properly, you need to seat yourself on my cock before I strap your hands in place." Arvus explained with a smirk, “I can hardly reach down and guide myself into you, or you do it yourself when strapped down. So for that to happen, I need to be fully aroused which is what you will do."

“You've got to be kidding me," Sabrina muttered, before resigning herself to her fate. With the impressive specimen of masculinity standing before her, she gulped nervously and imagined just how big he really was down there. She eased herself down onto her knees, noticing the bristling delight shiver up Arvus' barrel as he watched a woman kneel for him. She kept her head down as she crawled between his front legs, his heavy hooves pattering on the floor as she disappeared from sight beneath him. She immediately found herself draped in his shadow, surrounded by his massive thick, powerful legs and shaded by his body overhead. She crawled until she knew she was positioned between his hindlegs, where she could begin to detect the heat and the tinge of his more animalistic urge in the air. When she finally lifted her head, she was surprised when something thick and fleshy bumped the back of her head and slipped over her brow.

She had been expecting to find the stallion neutral and unaroused, however it seemed that the prospect of finally breeding after so long had gotten ahead of him. An entire foot of mottled horse cock was flopped out in front of her face, entirely soft and pulsing softly. It hung over an equally ample scrotum, hanging heavy and taut with the two over-filled testicles inside. He was a picture of masculinity, and yet she knew there would be so much more for her to take once she made the centaur fully erect.

Arvus had always been well-kept, surely to compensate for his more bestial build. He always looked quite clean and professional in class, and there were even some moments where, with his legs hidden behind a lectern or lab table, it was possible to mistake him simply for a very tall, handsome human. However, from where Sabrina knelt it was the exact opposite. From where she was, with his upper-body hidden from sight, it was hard not to think of him as an entirely feral horse. A fragrant sheen coated him down here, and every breath was tainted with the potent scent of an eager male looking to sow his seed. She wasn't sure if it was supposed to be a natural aphrodisiac, but she couldn't help but feel her mouth and nostrils tingling and her head get a little fuzzy with her own budding carnal desires.

“While your breath does feel nice on my shaft, it will not get me hard, Sabrina," Arvus remarked matter-of-factly. A blush bloomed in her cheeks and she sat herself back, putting some distance between her face and the pole of flesh she was meant to stimulate.

It was an intimidating task, made all the more difficult by the fact that this was her teacher. She'd never thought about him in such a manner, and now she was giving him so much more than she'd have imagined on the way down to his office. She'd certainly never realised he was like this. In her mind, she could hardly believe she'd agreed to his offer.

Her hand gingerly reached out and grasped the middle of his penis, her fingers sinking into the hot flesh of his cock as she gave the beast's half-hard prick a squeeze. It was shocking to think that he still mostly felt flaccid as she felt a dull throb in response to her initial touch, and she swallowed anxiously at the thought of how big he might grow when fully aroused. He remained thankfully silent as she began to rub her palm back and forth across his floppy equine shaft, feeling it slowly begin to drop further and grow firmer under her cautious attentions.

The smell of him was intense, reminding her constantly that this was no human she was getting herself involved with. His balls were almost visibly steaming in the cool office air, and the scent of his masculinity rolled off those weighty orbs as they lightly swayed with her actions. As inch after inch of his pride swelled gradually, she began to feel a deep sense of foreboding as she realised that in the few moments she'd been stroking his cock, it had grown to nearly two feet long.

A sudden throb tugged his erection from her hand, as the now-firm equine breeding organ slapped firmly against his underbelly. Stepping back a little, Sabrina shuffled out from under him as she looked at the immense slab that she'd coaxed from his sheath in awe. It was as thick as her arm and over two feet long, and she looked up to see its owner smirking down at her as she returned to her feet.

"That will do nicely," he told her gruffly, "I offer you one last opportunity to change your mind, Sabrina. If not, please work yourself into my harness. I will need you to get my cock into you, and then I can finish binding your arms. Once harnessed, my dear, you need do nothing for the rest of the day."

Sabrina hesitated for a moment, looking down at the harness attached to the centaur and swallowed nervously as her throat grew dry, yet at the same time she felt a flush of heat run through both her cheeks and nether regions. One day, one day of being fucked by that massive, incredibly thick and hot horse cock and the path she wanted in life would be set. Even if she got pregnant it wouldn't stop her goal of a job in magical forensics. Arvus' cock was most certainly beyond anything human, but that also made her loins tingle. The centaur was certainly a picture of masculine virility.

“Let's do this," Sabrina eventually mumbled, crouching low and crawling back underneath the centaur, once more becoming surrounded by the sense of a powerful, male beast. Just in that short time, the potent smell of an aroused male had grown significantly as two feet of pure maleness bobbed beneath the barrel chest.

She stared at the mostly black shaft, mottled with pink splotches and glistening slightly with the faint light reaching beneath the centaur's legs. After a moment she dragged her eyes away from it to the harness, looking over the numerous straps as she quickly worked out the separate sections. Four holster-like sheaths for both her arms and legs, with a number of straps to hold her torso close and another to keep her head supported.

Rolling onto her back she lifted one leg and slid it into one holster, pulling the straps tight enough to keep her leg in place while leaving some slack to let her move. She copied the same action with her other leg until they were both nestled against the warm, soft flanks of the centaur. It meant her legs were spread wide open, completely exposing herself for penetration, her ass raised slightly into the air while her back still rested on the carpet of the office floor.

Sabrina looked up at the horse cock then the belly straps, licking her lips nervously before she undid several of the larger belly straps and slipped them beneath her back. She reached up, gripping the harness itself and lifting herself up while reattaching the straps and tightening them. Suddenly, she was no longer on the floor, but nestled securely up against Arvus' underbelly. She could feel the fine, soft hair of his belly rubbing against her breasts,and even the faint sound and feel of the centaur's powerful heartbeat. Perhaps more notably, the entire two foot length of the formidable breeding organ was now trapped between them.

The slick, hot length of cock flesh almost felt like a searing brand as it travelled up across her vaginal slit, past her navel and up to her breasts. She had the errant thought that if she bent enough she might be able to kiss the tip of the centaur's cock it was so long.

“You know you're too long right?" Sabrina asked, staring at the slanted, flat head and the urethra that yawned as she watched. A large bead of pre seminal fluid appearing and dribbling down to drip onto her.

Her whole body rocked slightly as Arvus chuckled, “Oh don't worry, I know. As much as it's a pity I can't sheath every inch inside, I won't force it. I'll make sure to stop at the limits of your body."

Sabrina shivered at the promise in his tone, but couldn't argue against it. She had faith that Arvus wouldn't go too far, despite the male being much too large for her smaller human body. With her body only loosely held up by the straps, Sabrina shifted herself up the underneath of the horse body. Sabrina couldn't hold back a gasp and moan as the shaft slid down and across her cunt, the heavy, thick weight both spreading her open slightly and pressing down on her clit.

It was like she was getting an intimate feel of Arvus' entire cock as it dragged down across her, the firm medial ring dragging a sharp hiss from her until she finally stopped as the cock's head retreated enough to nudge at her entrance. Sabrina was breathing heavily as she felt warm, sticky spurts of lubricating pre splashing against her vagina. She could feel the full size of the broad head against her entrance, and it felt even bigger than she thought. It was a pivotal moment though, and rather than give herself time for self doubt, she pushed herself down, crying out as she felt her vagina stretching open wider than she ever thought possible.

Even Arvus grunted as natural tightness and warmth wrapped around the first few inches of his shaft with the form-fitting grip of a condom. He stamped his hooves in carnal delight and clenched his fists, listening and taking pleasure in the young woman struggling to take him. Even if she wasn't a virgin, her previous partners would never have helped her take something so thick. In response to his penetration, her body began to lubricate her passage, slickening his head as he pushed and shoved even deeper while she attempted to push herself down. His girth stretched her lips to their limits and ground hard against her clit, making her gasp, groan, and clench hard as two inches of pulsing horse cock became four. Gritting his teeth, Arvus huffed as his cock gave a single, mighty throb, nearly filling her vaginal passage with pre-cum in a single heavy shot.

“You might be the tightest troublemaker I've ever done this with," he remarked, his breath sounding laboured as he struggled to hold up to the tightness and pleasure. Not even half of his cock was inside her, but finally having something to stimulate him after such a long period of abstinence was making him eager. It took him all the willpower he had not to simply mount his desk and start going to town on the woman strapped onto his cock.

“Please, stop pushing," Sabrina begged, her fingers white-knuckling the straps that bound her hands. What little forward sway she was allowed was used to bounce her back against the shaft impaling her, wedging him deeper and deeper every time his hips errantly pushed her.

“We'll need you properly situated before we can begin," Arvus replied, trying to hold himself back even while she made no effort to move herself deeper. “It will just fall out if I'm not in deep enough, and we'll need to start this process all over again. Once I can feel your cervix, then I will consider you secured."

“M-My cervix?" she asked, fear edging in her voice. That sounded so deep, and yet she knew it was nothing compared to his full length. “C-Can't you just use magic for this? To make it easier?"

Arvus chuckled and shook his head, even though she couldn't see it. His amusement was enough of an answer for her anyway. “This isn't supposed to be easy for you, my dear. Consider this your make-up exam, for all the tests you've failed beforehand."

Sabrina groaned, her legs shaking in their straps from the exertion of being split in two. Her arms squeezed tight as she tried to hold herself up, but ultimately she just had to let the straps support her and submit herself to the centaur. With him still sitting four inches inside her, it was already too late to save herself the embarrassment and discomfort.

“I'll be generous, Sabrina, as I am your teacher and this is ultimately about your education," Arvus couldn't help but fold his arms over his chest and almost sneer down at where he knew Sabrina's head would be hanging beneath him. “ If you can recite to me the recipe to brew a potion of elasticity, I will let you have one. That should make today much easier for you. It was even covered in a lecture last week."

There was no greater insult to her injury. They both knew she didn't know, and so there was no point in answering. Instead, she buried her face in his soft underbelly fur, did her best to spread her hips even wider, and tried to push onto him again without a word.

“Dear Sabrina, this was your problem all along. You never ask for help, and so of course you can't receive any. It's why you're in this predicament in the first place." Arvus surprised himself by how much he was enjoying taking his stubborn student down a peg. “I think you know what you need to do to make this right."

Sabrina couldn't bear to pull her face free of his body, so she simply spoke against it. “Please help me get it in, Professor Arvus..." she mumbled in defeat, and her entire body suddenly clamped down as the centaur stallion's urethra kissed her deepest barrier.

The sudden thrust from the much older male left her feeling faint, her young body unprepared for such an incredible stuffing by that unyielding slab of equine meat. It was a shocking reminder of the difference in their size and strength as he crammed every available inch of her vaginal passage full of his immense shaft, and yet not even half of it was truly inside her.

A firm bulge felt like it was pressing up against her outer lips, the stallion's pronounced medial ring keeping the lower half of his erection from spearing her through. She trembled at the sensation of his girth stretching her to the limit, no magic used to assist in her ability to take such a monster cock.

"F... fuck..." she breathed heavily, trying her best not to think about what kind of mistake she was making. She could feel his powerful heartbeat through that titanic organ, not to mention the mountain of brown belly fur that stretched across her vision. It would be all she would see for the rest of the day.

Giving his penis an experimental flex and hearing the student gasp under him, Arvus was satisfied that it wasn't about to fall out anytime soon. Turning a little, he smirked as she swayed slightly in the harness, shifting his maleness within her and making her entire tunnel tremble. Every little thing he did from now until the end of the day would result in his cock sliding in and out of her body. With a firm grip on the straps near his front, he pulled them hard to complete the bondage. Sabrina grunted as her arms were pulled up tight to his body, ensuring she was utterly at his mercy as she splayed beneath his barrel.

"I shall don my coat before we leave," he told her calmly, grasping his wand once more, "but first, a few enchantments. You wouldn't want your classmates knowing that you're riding my cock while I'm giving a lesson, would you now?"

“No," Sabrina said weakly, gasping loudly as Arvus turned and took several steps towards where the centaur had hung up his robe. Such a simple movement and the horse cock filling every inch of her vaginal canal had shifted back and forth several inches. The hot, thick breeding organ was stretching her so wide that she could feel strongly even the smallest twitch of the shaft; so a small thrust was enough to make her gasp and her core clench around Arvus who hummed in delight. She was rewarded with another large gush of hot, lubricating pre as the shaft jerked in response.

“Oh yes, I am most certainly going to enjoy today," Arvus commented out loud as he raised his wand at his robe, mentally calling up a list of possible enchantments. His student was so tight that when her body actively clenched down on him, he had to strongly resist the urge to neigh and slam his cock home.

“Let's see now," Arvus said with a smirk, speaking out loud so Sabrina could hear him clearly, “A spell of silencing of course. We don't want anyone hearing your moans. Another to keep the smell trapped in; I'm sure the smell of sex is going to get quite potent. Finally, I think one to trap any mess we make that escapes your tight cunt." The centaur chuckled, deliberately flexing his stationary shaft inside the hot, wet sheath and enjoying the moan he elicited from Sabrina, “With how wet you are, and how many times I'll likely cum today, we'll certainly need it."

Arvus finished layering the magic over his robe then picked it up and with a flourish, let it sink over his equine body and around his human torso. The garb reached down far enough to clearly hide the harness and as well as the straps running over on top, completely hiding away the student riding his cock. The hem reached low enough that even when walking he wouldn't have to worry about anyone spotting something out of place but high enough he wouldn't trip over it.

Sabrina watched as the robe slid around her, causing the light around her to dim, though there was still enough to see. The effect was almost immediate as she could smell the difference in the air immediately. With her face pressed up against the soft, brown fur she could strongly smell the musky, masculine odour that seemed to be the centaur's unique scent. The smell of her own arousal and Arvus' had also started growing, and when the robe covered her, its strength spiked, seeming to make even the air around her grow thick and increasingly potent.

“Now I won't be able to hear you if there's anything you need to say Sabrina" Arvus warned her, “So feel free to be as loud as you want. Now I have to go to class. Your potions class coincidentally, so do try and pay attention. Just because I'll be raising your grade is no excuse for you to miss out on your education Sabrina."

The soft clopping of Arvus' hooves against the floor echoed around beneath his robe as if she were in a cathedral, amplifying the noise but not letting it escape. This was the same for the fluid squelching between her legs, and her own gasps and groaned as he gave his covering one last check and left the office. She could hear the difference immediately as he entered the now bustling hallway, with dozens of other students moving around him in herds. She could see their silhouettes projected on the inside of his robe, could hear them talking, laughing, and even politely greeting their centaur professor. Arvus simply replied as if nothing was different, his voice measured even as his cock throbbed inside Sabrina and bounced with every step.

The alternating movements of his thighs made her sway back and forth, grinding his cock against her walls and sliding a few inches in and out. Every bump against her cervix made her gasp and shout, but no one could hear her. They were getting close enough to make the hem of Arvus' robe flutter, but no one knew she was there. She could just imagine it, a clumsy student tripping right there. Trying to catch himself on the sturdy centaur, but tugging his robe off by mistake. Hundreds of students, her classmates, staring in disbelief as she rode, naked and speared, under their teacher's belly. The waft of trapped breeding musk that would escape and fill the hallway. Her cheeks flushed with colour, and she buried her face in the centaur's stomach fur to hide herself from the embarrassment, even if the errant thoughts had made her pussy sound even wetter as her teacher slopped through it.

It seemed like Arvus was taking the scenic route to his classroom, as she suddenly felt the warmth of the sun bleeding through the cloak. It got hotter, and all of that heat was contained as it infused with the stallion's blooming musk. Every laboured breath was mind-numbingly masculine as sweat seeped from the pores on his underbelly, and made the ballsack bouncing and sliding around behind her cling with sticky moisture to his inner thighs.

“What a beautiful day," Arvus remarked casually, taking a deep breath and stretching his body out. From his hooves up to his head he stretched his body, including pushing his hips in towards the front of his body. Sabrina's straps held firm, keeping her in place as his cock surged forward and trembled, grinding hard against her cervix.

“H-Hold on!" she cried, digging her nails into his sides and holding on tight. He couldn't hear her, but he would certainly be able to feel her struggling against him. It only mattered whether he cared or not. She gasped again as something firm pressed against her already overstretched pussy. “Is that your…?"

His medial ring, pressing hard at her entrance and demanding entrance, as if there was anywhere else for it to go. Her cervix was already holding the rest of his shaft at bay, and to allow any more inside would mean the collapse of her own inner barrier. Sabrina grit her teeth and tried to pull herself forward, to ease the pressure on her passage, but it was no use. She gasped, grunted, and groaned as it felt like her body was going to be speared open, the pressure on her insides too much to take. Then Arvus relaxed, returned to his natural posture, and continued his walk back towards his classroom, his stiff medial ring now grinding persistently against her outer lips and her clit.

“A shame it has to be spent inside the classroom all day," he concluded wistfully, while beneath him Sabrina wondered if her cunt would ever close up again. It had only been a few minutes since he'd entered her, and already she felt entirely ruined by his incredible equine girth and length. Every little movement for him set off every little nerve in her body, and she let out an involuntary moan as his casual trot continued to fuck her at that agonisingly slow pace.

His erection never showed any signs of softening, the young woman unaware that centaur stallions were effectively limitless in their virility and that she would get no reprieve as the day wore on. It was evident the perverted stud was enjoying every moment of it, despite not giving a single outward clue that he was stuffing a student full under his cloak.

With her arms and legs bound and spread, her noises silenced, and her existence hidden from the world as Arvus entered the Potions classroom with a brief wave of his hand, it was like she'd ceased to exist at all. If he wanted to, he could keep her like this for days, and she would have no say in the matter, no way to resist the centaur's actions.

She could hear the conversations as he walked past some of her classmates; of homework, potion brewing and other frivolity. None of them could know she was under that glossy black cloak as Arvus took his place at the head of the class and let the head of his cock nestle firmly up against her inner barrier.

"Please get out the ingredients listed on page seventy-two of your textbooks from the cupboards," Arvus requested, "today we will be attempting to brew a Selsior Concoction. Can anyone tell me what this particular brew will do?" There was a moment of silence, Sabrina considering that there were probably a few hands raised as she tried to shuffle a little on her bondage.

"Yes, Felix?" Arvus selected.

"It's a medical potion that can... uh... repair damaged skin tissue," Felix responded after a brief moment of hesitation.

"Can you be more specific?" Arvus asked with a nod, and Felix continued.

"It's usually used for treating injuries where skin has been stretched beyond its natural ability to heal, isn't it?" the student added, "like, for people with bad stretch marks?" The centaur smirked, giving his cock a powerful flex that made Sabrina gasp at the sensation.

"Indeed," the teacher confirmed with a smile, "very good, Felix. It can repair torn, cut or stretched skin, in fact, though often with a deep injury we would use potions that heal more than just skin. Some often use Selsior for cosmetic, or anti-ageing purposes. Now, head to the cupboards and collect what you need."

Beneath the centaur, Sabrina grimaced at the implication. There was little doubt he'd chosen this potion as a statement to her, and she wondered just how much of it she was going to need after a day speared and stretched upon this monster cock.

“Now then, proceed according to the instructions given in the book..." Arvus began, and Sabrina listened as her professor began going through some of the finer details involved. Using a board at the front of the classroom to better describe and reiterate some points. Sabrina was certain that Arvus was doing it on purpose as the centaur frequently moved several steps back and forth, each step making the massive horse cock thrust inside her in short, erratic movements.

Sabrina did what she could to listen to the lesson, feeling a certainty deep inside that she would need one by the time Arvus was done with her. Already she felt like the strikingly hot, firm shaft buried inside her cunt spread her wider than normal, and Arvus was just sheathed inside her. His thick, slick cock wasn't giving her vaginal passage time to rest and recover as the broad, spade like head continued to hammer at her cervix. Each time it made her body shudder and want to cry out.

Arvus began to wander around the classroom, observing as his students worked diligently at processing the ingredients and forming the potion. Not once did any of them question the empty desk where Sabrina normally worked, and they all were so diligent as they focused on their work. He paused by one student and offered a few pointers where they had paused in confusion. Arvus had to struggle not to smirk too obviously as he deliberately flexed his cock inside his naughty little cock sleeve, wondering how much she was able to understand and remember.

Sabrina moaned as the cock flexed and ground against her clit, burying her face into the musky underbelly as she struggled with what she was feeling, while trying not to forget what she could hear. It was even worse as she knew that the centaur was right next to her fellow students who were so oblivious to what was going on, hidden beneath his robes. How the wet, lewd sounds of the horse cock sliding in and out of her with every step sounded so loud to her ears. The growing smell of sex and musk building up so intensely, trapped within the spell of the robes which drove the atmosphere to grow thicker and warmer.

Time passed and Sabrina's mind felt fractured as she remembered everything Arvus had said about the potion. So many little tidbits that she felt she could make it easily now, only every memory of the potion was accompanied by the distinct and intimate sensation of Arvus sheathed so deeply inside her. A flex or thrust as if to make her take special note of something. She was panting, her whole body on edge and twitching, responding to the slightest twitch or spurt of pre deep inside her; everything felt so sensitive and she didn't feel like she had loosened at all, Arvus feeling as thick as ever in her tight channel.

“The class will end here today," Arvus called out, “Please put away your ingredients and equipment then clean your workstations. Tomorrow we will be looking at the common stamina recovery potion. Please read up on it and the details of its effects."

Sabrina gasped for breath as Arvus finally stopped walking, doing her best to try and calm down and relax. She felt just as hot as he was, her face flushed and her body dripping with sweat that his containment spell collected. She listened to the bustle of students leaving the lab, the sliding of chairs and the running water rushing through numerous faucets. Cauldrons and utensils banging together, creating a cacophony that might have drowned her out even if there wasn't a silencing spell on her.

Even so, something wasn't quite right as Arvus waited for the last of his students to file out. He was twitching and jerking his hips in minute motions more than usual, making the young woman bound to his cock tense and shudder. It felt like there was so much energy he was holding back, as if he'd grown weary of the rules of the game and just wanted to play with his toy. The minutes seemed to tick by at an agonising speed, but finally the last lollygaggers shuffled their way out of the classroom, leaving the impatient centaur to his own devices.

Sabrina yelped as she was suddenly thrown upwards, light flooding into her cage of equine muscle and cloth. Below her the countertop of a lab station came into view, and the furniture groaned as the adult centaur's hooves clattered onto it and it was forced to take his weight.

“I couldn't help but glance over at your empty seat while I was doing my rounds," he huffed, his voice deep and rich with lust. It seemed that, at least for a moment, he would let the facade fall to show Sabrina just how much he was enjoying this. “I kept waiting for someone to ask if I knew where you were. Waiting to overhear your classmates remark on how they hadn't seen you this morning. No one did, but it got me surprisingly riled up thinking about them worrying about you while you hung right here, clenching on my cock."

“I-I didn't think you were this twisted," she shot back, but there was no reply. Not even an amused chuckle at her attempt to verbally defend herself. It seemed that even with his cloak lifted from the ground, as long as it was on the enchantments still worked.

“There's still so much of the day left, but I can't wait any longer. I'm going to fuck you now, Sabrina, while we have some time alone," he grunted, and on the other side of the room she heard the distinct thunk of the lock on the door clicking shut. “You've been rubbing against my medial ring all morning. I think it's time to introduce you to it properly, perhaps I can even kiss your cervix with it, as well."

Before Sarah could even prepare herself for what was to come, before she could question what he was going to do, the centaur pushed her down against the lab table and thrust himself forwards. Her eyes widened and her entire body tensed up in shock as that immense slab of breeding flesh suddenly slammed into her cunt, a loud cry of pleasure and pain escaping her lips to be muted by that enchanted fabric.

It was an entirely different situation to simply have his cock inside her, and get properly fucked by it, as the adult centaur began to pull back and thrust himself into her again and again. With the classroom empty and locked he could go to town brutally rutting his student, using the harness to keep her from sliding back away from him as he pumped his equine shaft in and out of her body with brutal force.

"F... fuck... oh... g... gods..." She gasped as her body tried to cope with the feeling of his blunt dick hammering at her inner barrier while that fat ring of flesh in the middle of his length stretched her pussy lips wider than she'd thought possible. With a loud grunt from the horny stallion, he managed to force that medial ring inside of her with a heavy pop, locking his penis in place briefly as the next few thrusts didn't dislodge his erection from her insides.

With a hard tug he pulled the ring from her abused sex, leaving her stunned briefly before he rammed it right back inside, ensuring her muscles didn't tighten up on him as he began to fuck her deeper than before. With the admission of his plump ring, his cockhead was putting even more pressure on her cervix as he continued to thrust away into the young woman bound to his underbelly.

"You're exceptionally tight, Sabrina," Arvus smirked as he enjoyed himself within her core, "let this be a lesson to you, from your Potions teacher. Your womb is now my cauldron, my dear, and my sperm the only ingredient that is needed to brew a rather wondrous concoction of life."

“M-must you?" Sabrina gasped out as the thick, ridged medial ring plunged in and out of her, almost strumming at her entrance. Of course, Arvus couldn't hear her and so continued on.

“It will also be a good encouragement for making sure you remember the Selsior potion preparations. Even mares grow round when a centaur fills them," He grunted and Sabrina cried out as the thrusts grew erratic, the medial ring disrupting any rhythm she could get used to. “So with such a small, tight cauldron to fill, you're certainly going to swell with just my ingredients, let alone the foal you'll soon bear."

Sabrina didn't reply this time, just rocking and crying out with pleasure as the cock's head bounced hard against her cervix repeatedly while the medial ring plucked inside and out of her. It was just so difficult to grasp the concept of becoming a mother to a centaur foal while Arvus was rutting her on her own desk. Her eyes widened as she gasped and shook on top of the rocking from each thrust; the large, broad head grew wider inside her, in three thrusts feeling like it flared to almost twice the width right up against her cervix. It was just too much for her as she screamed, clamping down hard and erratically around the horse cock as she came moments before Arvus did.

A massive, powerful jet of thick cum blasted right at her cervix, immediately pushing through into her womb. Blast after blast of hot, potent centaur seed hit the entrance to her womb, rapidly filling up the small space between with the wide, flared head acting as a barrier. With only one way to go, and pressure building with each subsequent mighty throb of spunk, Arvus's foal batter flooded into her womb.

Sabrina moaned and quivered, shaking as she felt Arvus's massive length sheathed inside her throbbing, her womb feeling strange as hot, creamy sperm splashed all over and began to rapidly fill her. Arvus hadn't been jesting as the centaur neighed with a seemingly endless orgasm. The cauldron of her womb filled and swelled, stretching her as Arvus unleashed months and even years of pent up desire inside her core. So much potent, very non-human cum, all trapped deep inside her, almost certainly with the fertile semen charging towards her vulnerable eggs. There wasn't much use denying the obvious when she was now being filled by a very horny, virile centaur.

"Oh gods…" she groaned, holding tight to his underside as he filled her up. She screwed her eyes shut as each pulse of life through his shaft rubbed against her clit and stretched her in a way her body couldn't deny. She hated the feeling, but she could tell her sex was getting wetter, and not just from his cum. Her body, whether she wanted it to or not, realised that it was getting impregnated by the male lodged inside her, and so she was milking him for every drop with extra lubricants and whatever clenching her overstretched muscles could still perform. She was so full, her body shaking from head to toe, and yet she couldn't tell if each gushing spurt of equine cum was getting any weaker. She felt like he could pump her full until she burst.

“Mmph, you're going to look six months pregnant by the time you come off my cock," Arvus grunted, bearing down on her still. He could feel her stretching against his underbelly, her womb bloating with cum like it would bloat with his foal. Even one load was too much for her, and yet he planned to give her more before her day beneath him was up. She felt so good inside, exquisitely soft and tight even after he'd put her down against the bench and fucked her like a mare. It was like she was moulded to fit him; a human sheath for his equine penis. She took him well, despite her protests, but he couldn't help but feel like the back half of his cock was starting to feel cold. He knew he couldn't fit it all inside, but she had been flexible enough to take so much of it already, now hugging tight around his medial ring. What were a couple more inches?

His orgasm was beginning to dissipate, leaving his sperm to bubble and ooze from his urethra to join their comrades already brewing in her womb. Her poor passage was a mess, stretched and rubbed raw by his cock. Her cervix was heavily dilated, opening to let his sperm through as if he were a proper male of her own species. Shoving and grinding down on her, there was no doubt in his mind that her body was accepting its place as his condom, and opening her reservoir for him. Arvus didn't warn her, didn't wait, and with a moment's loss of control, thrust hard into her again. His flared tip pounded against her weakening barrier, sloshing the copious amounts of sperm around inside her, but it held firm and did not allow him any deeper despite his overpowering strength.

“St-Stop! Stop!" she cried, and for the first time she tried to close her thighs to restrict his movements. Her hands scrabbled and pounded at his sides to get his attention, and she did what she could to shake and squirm in her bindings. However, with him already buried so deep inside her there was next to nothing she could do to slow him down. Her legs pressing in from both sides only made her entrance feel tighter, and spur the lust-drunk stallion on. He slopped thick globs of cum out of her tunnel as he drove back and forth through his own load, splattering cum against the insides of her legs, up against his stomach, and even back against his swinging scrotum some inches behind her.

When Sabrina's struggles redoubled in effort, Arvus came to his senses and slowed his frantic pace. He slowed his grinding to a halt and stood still, catching his breath and letting his heart slow while he could feel the steady vibrations of her groaning against his belly.

“My...My apologies, my dear," he remarked after an awkward silence, and cleared his throat. “It's been awhile since I've had a mate as good as you strapped up beneath me. Perhaps too long. I lost my composure, but I'm glad you were able to hold up through it."

The young witch shuddered in pleasure and a little pain as the centaur calmed, panting from such an intense fuck. She couldn't believe he'd just pounded her half to death on a classroom table, and yet she could feel every throbbing inch of evidence between her legs. The smell of stallion sperm had filled up the space around her, even as every glob that leaked from her ravaged pussy was magically vanished by the enchantments permeating his cloak.

Stepping away from the table and leaving her to hang completely once more from the harness, the teacher straightened his cloak slightly and began to head for the door. Unlocking it with a wave of his wand, Arvus could feel her body sliding up and down on his unyielding erection with the added lubrication of an utterly immense load of his virile stud-seed.

Students hurrying to their classes passed by on either side as he strode through the halls, blissfully unaware of what one of their teachers was hiding. Sabrina felt lightheaded; after such a rough rut, her body felt tender and foreign, unfamiliar sensations keeping her feeling a deep sense of concern. It was becoming more and more clear that she was not just powerless under this beast, but that his cloak rendered her existence utterly invisible to the wider world. If he didn't want to let her go at the end of the day, what recourse did she have?

Arvus made his way down to another classroom, and before she'd had much time to think about her situation, Sabrina was once again listening to his educational words. It was curious; she'd never really paid quite so much attention to his lessons as she did mounted on his penis. Now that he'd fucked her hard once already, just laying there in the padded harness, with the occasional flex of his shaft inside of her, or a brief thrust as he stepped, was almost soothing. That thick, sperm-dense gel kept her tunnel from feeling the intense friction she'd experienced before his first orgasm in her body.

Between lungfuls of his raw, sexual odours, she could smell his natural scent with her nose brushing up against his underbelly. It was oddly comforting, and she inhaled it greedily while listening to him work his way between students and their endless questions and comments during his classes.

Where before every slight twitch, every thrust inside her tautly stretched channel would shock her, it felt easier now. She wasn't any looser, the pleasure just as intense as she rocked back and forth on the shaft that hadn't softened in the slightest. Yet after the intense fucking on her desk, it was almost like she had acclimatised to it somehow, able to focus more on Arvus' words even as the horny stallion rocked up against her battered cervix.

She listened in as Arvus instructed his class, rarely seeming to stand still, even if just to take a single step back or forwards, shoving that extra inch inside Sabrina. Even through the slight haze of pleasure and intense, masculine musk, Sabrina felt she was somehow focusing better than normal. It wasn't her class, but as a professor in magical potions, Arvus taught multiple classes and different years, so she was listening to it all. A massive horse cock, slick with spent sperm rocking inside her without pause as Arvus went other potions and theories with her riding along.

The class wrapped up eventually, but this time Arvus didn't find a desk to rut her on and instead headed to another class, with Sabrina bouncing along beneath him, everyone else blissfully unaware of her situation. Each long stride as Arvus strode down one corridor after another drove the hard shaft deep inside her, the medial ring popping in and out with every firm thrust. Sabrina repeatedly moaned as Arvus took his time moving to his next class, happily stopping suddenly to greet a student or fellow professor. Each time, Sabrina cried out as she found herself slammed down on the male's girth, the momentum carrying her down so the rigid medial ring caught and dragged inside her, not stopping until he bumped up against her poor, abused cervix. She was breathing in the comforting masculine musk so heavily now, her every gasp dragging in more in a repeating cycle.

“Two more classes until I'm finished for the day," Arvus commented in one conservation and Sabrina shivered as the cock flexed inside her. She suspected the centaur's mind went to the same place as hers, in which that was a long time left for her to be riding his cock. Time seemed to jumble forwards as she found herself listening intently in classes even as the very non-human cock constantly shifted within her cunt. Even with her passage full with the male's virile sperm, she could feel more pre spurting inside her with every twitch and jerk. The lessons burning into her mind even as she felt her swollen womb rubbing up against the hot, furry underbelly of the centaur.

She barely registered when his class ended, only noticing the sudden stillness between her legs as he stood still and watched his students leave. It was almost unnerving, not feeling the stretch of his medial ring at her lips or the harsh bump of his tip against her barrier sending jolts up her spine. The warmth of his shaft inside her was almost comforting, but it was nothing compared to the sloppy heat of his sperm lubricating his movements. The longer he stood and watched, the deeper her unrest grew, until before she knew it, she was shifting her weight forward to swing herself beneath the stationary stallion's belly. For the first time since they had begun, Arvus let out an audible grunt of surprise, his cock jumping with almost painful strength inside her. Some of the lingering students glanced back at their professor curiously, but never thought much of it more than an errant sound and moved on. He had probably stubbed his hoof or knocked his hand against the hard wooden desk on accident, which also explained why he began to rock his hips forward and back slowly, to help distract from the sudden jolt of pain.

As soon as the door shut behind the last student, Arvus allowed himself a chuckle. “You really are a surprise, my dear. Here I thought you would appreciate a moment's reprieve, and then you start desperately trying to work me up again. I'm very curious to hear your thoughts on that once we're finished for the day."

Sabrina wasn't even entirely sure what she was thinking. Her head was swimming with jumbled up thoughts, not just about her position and her bestial predicament, but of ingredients, mixtures, and tonics. Reactions that she had read about with glazed eyes now made perfect sense, and made her pussy tingle at the thought of them. Recipes that made her heart race and her loins burn. If she had learned so much before, she never would have been put in this position, but she never would have learned so much without getting fucked into submission by her equine professor.

She hadn't realised that he had fallen still again, and the movement of her hips had doubled to make up for it. She was well and truly fucking herself on her centaur teacher's cock now, the pace entirely set by her while he stood and waited. She realised that she should have stopped, but the burning in her core was simply too great to ignore now. She heard the door open, more of her classmates filed in for the afternoon's final lesson, and yet she had lost the part of her that worried about getting caught. She was vocal now, huffing and moaning into Arvus' strong stomach while she used him, instead of the other way around. He smiled, but the one student he was smiling for couldn't see him.

He surged forward, stepping out from behind his desk to begin his lecture, and in the safety of her private fabric sauna she screamed aloud and came with mind-numbing force. None of the students could see her squirming in her bondage, see their classmate impaled on the largest cock in the university, Sabrina panting as she came down from her orgasm. Everything between her legs was a mess, mostly horse cum mixing with her own output to create a thick lubricant that clung to her inner thighs or was vanished as it dripped from their union.

Arvus continued his last class for the day like nothing had happened, requiring some effort from the older male not to show how much pleasure he felt from his living cock sleeve. It was difficult not to let out a satisfied smirk as the young girl under his barrel went from unwilling toy, to eager stallion-slut over the course of the day. After her efforts, Sabrina hung limp in her harness and allowed him to finish up with the students while she recovered, her cunt still stretched brutally by that girth slab of equine meat. A true stud, Arvus hadn't once let his erection wane within the confines of her body, nor would he allow it of himself to give her any reprieve.

As the students began to exit his class, books tucked away and bags slung over backs, he farewelled them politely, giving each a wave as they passed. Once the final one had left, Arvus headed out behind them and closed the door, heading off towards his private quarters where he lived on campus. For a centaur such as himself, special arrangements had been made, as human rooms were not quite fitting for a beast of his stature. Silently he walked, feeling Sabrina slip up and down his shaft as they moved, satisfied that she'd held up her end of the bargain. Yet... he had one last load to give her, and in the privacy of his room, he was not going to be gentle about it.

It only took five minutes to return to his room, Arvus locking the door behind him, with magic this time to ensure he wouldn't be bothered. Casting his cloak aside, Sabrina was surprised to see the inside of her teacher's private room for the first time, and to be freed from that intense, musk-laced veil of silence.

"Welcome back, Sabrina," he chuckled, "I trust you had a very fulfilling day of school?"

Sabrina didn't answer immediately, breathing heavily as she looked around the room a bit dazed as a rush of clean air circulated around her. Breathing it in only made her realise just how strong, how potent the centaur's musk was. The cumulative smell of hours of sex, sweat and musk having filled her every breath to the point she had forgotten anything else until now.

“It was... very fulfilling," she breathed out heavily, unable to hide the slight strain in her voice.

Even now Arvus was sheathed inside her and as hard as ever, his cock flexing occasionally as the centaur rocked minutely into her. She was stuffed, her womb feeling full and heavy with the stallion's sperm while her channel quivered around the shaft, feeling almost twitchy from stretching so wide for so long. She was so slick, and her nerves feeling somewhat raw yet she still felt so good as the centaur rocked into her on purpose.

“And did you learn anything during potions class?"

“Yes professor, I remember... most of the lessons," she admitted, sounding a bit weak at the end.

Arvus hummed, a smirk growing on his face as he told Sabrina, “It sounds like you learnt more while riding my cock than you did in several of my lessons put together then. Who knew that being my cock sleeve was such a good learning aid... or that you would enjoy it so much."

Sabrina blushed though Arvus didn't see it as he cleared his desk with a measured calmness, stacking paperwork and putting it on the floor. He could feel his cock jerking erratically as he thought about the last, good load he was going to fill her womb with, making him struggle not to rush and simply sweep everything off the desk. It didn't take long for his patience to wane though and he just dropped the last few books to the side then mounted the desk, dropping Sabrina onto it. Her gasp was mixed with his grunt as the position had her sliding down until his cock head hit her womb's barrier.

“Now before I let you go, I think we both deserve a final, good fuck without the cloak shutting you in." Arvus chuckled with a grin.

Sabrina whimpered as all of that weight was dropped onto her, just like before. With her back to the desk and his hips surging forwards, there was nothing to lessen the impact of the centaur cutting loose. Previously, either the straps had given her some wiggle room or he had been trying to keep himself composed, but now it felt more like that brief moment when he had lost control. Arvus wanted to have a good, strong rut to empty his balls with, and she had little choice in the matter. She could only decide if she wanted to love or hate the experience.

“P-Professor..." she gasped, hanging onto him tightly as the wet, dirty slurps of feral fucking started up again. His medial ring audibly popped in and out of her pussy as he powered through her, and now he could hear every bit of it. In fact, being able to hear the effect he was having on her only made him want to hear her more.

“I didn't realise how arousing it would be to have you call me that while I bred you," he grunted, ploughing through her tunnel with long, powerful thrusts that stretched her opening and pounded her cervix.

“Th-There are students...right outside..." she whimpered, white-knuckled as she took the ample centaur cock. “If you make me...if I make too much noise...they'll hear us..."

“My dear, perhaps you need to be strapped on my cock for more of your classes. You clearly haven't been paying attention during your time at this school," he teased. “Magic can do wondrous things, in case you've yet to notice. For the most legitimate student-teacher privacy reasons, the same enchantment that was cast on my robe is also on my door. That means you can be as loud as you want in here, whether you're whining about your poor grades, or begging for my cock."

“Oh...Oh gods..." she groaned, holding on for dear life as she was made to endure the stallion's unrivalled strength. She was sure that he was still holding back; there was no way her body could take a full-force fucking from a feral beast like him. It mattered little when it still felt like his erection was going to drive her in two. She was fighting the tension of the straps to stretch her legs as far as possible, opening herself up for the larger male to use. She could never truly get used to his size, no matter how long or hard he rutted her.

“Brace yourself, Sabrina. Consider this your true make-up exam. I want to know how much centaur cock you can take, and I think this stubborn cervix inside you is holding you back from your...Mmph...True potential," Arvus huffed, clenching his fists and leaning his entire body as he stacked Sabrina on her shoulders and started to pound nearly straight down into her pummeled, softening barrier.

The young student saw stars as her equine teacher began to fuck her with all the incredible power that a centaur stallion could muster. His immense cock, having been enjoying the depths of her body all day long, still demanded more from the woman speared upon its impossibly large girth as he rammed himself deep inside. The table below prevented her from resisting his thrust as he leveraged the angle of the harness and furniture to brutally ravage her in the privacy of his room.

Thick semen squelched out of her onto the desk from his earlier load as the solid shaft displaced his leftover genetic material, no longer enchanted to vanish as the sloppy sounds of mating filled the air. All she could see was the mountainous underside of his body as her inner barrier took every bit of force the older male gave it, his intentions clear as to just how deep he wanted to penetrate his student.

"A... Arvus..." she gasped, powerless in her bondage as she tried to form a coherent sentence. It briefly crossed her mind that he might just be causing permanent damage to her pussy with the day's activities, but that paled in comparison to just how much of a mess she would be if somehow she could fall pregnant to this insatiable stud.

"Please..." she begged, clutching at the straps. She didn't even know what she was begging for anymore, with no real certainty that things would end after he'd finished this final lesson. Her body didn't feel like it could take any more punishment, and yet deep down she knew that even if he offered, she wouldn't let him stop.

"As you wish, my dear," Arvus rumbled in response, and with one hard thrust pinned her to the desk and pushed the head of his cock through her yielding barrier into the fertile furnace of her womb.

Sabrina cried out, her muscles clamping down as the wide head of the centaur's cock pushed deep into her womb, hitting the back of it with that one thrust. Her body jerked, feeling almost out of her control as she felt Arvus buried in her core, her fertile chamber now vulnerable and completely exposed to the virile male mounting her. All thoughts of what she had been begging for fled, only the massive equine cock sheathed inside her mattered as she felt the already wide head flaring wider. The incredibly sensitive area almost electrified her with sensation as Arvus didn't stop thrusting while his breeding tool flared, only the extra width now stopped him from withdrawing through the cervix.

Arvus growled as he continued to thrust into the fertile chamber of his pinned student, feeling himself hammering the back of the womb even as his balls tensed, clenching almost painfully hard as he exploded into his climax. With no barrier to block him, this time his hot, potent seed blasted directly into the female's womb. Each small thrust inside her joined by another powerful wave of the millions of swimmers, trapped as the thick girth and flared head effectively plugged the entrance to her womb.

With the sheer force of the centaur's ejaculation, Sabrina could feel the powerful jets of cum hitting the back of her womb with shocking force. Heavy ropes of hot, thick seed joined the previous load, the volume already so much that she immediately began to stretch and swell to accommodate the increasing amount of potent foal-making batter. Her hands reached up, clenching the straps of the harness so hard her knuckles went white as the centaur continued to rock into her with every jerking throb of his shaft and subsequent spurt. Sabrina looked down, seeing in a daze how her belly was already round and with her womb stretching out visibly with each seed laden rope of horse cum within her.

“A-Ah...Arvus..." She groaned, her back arched against the equine's underbelly and his flared tip making a healthy bulge in her slender frame as he ground into her and ensured she was properly pregnant. She already looked like his child was growing inside her, even though it was only his fertile foal batter trapped inside her womb and flooding up her tubes. Something inside her body, chemically and hormonally, switched on in her brain, she just knew she was a mother now. She was going to show up for next year's classes heavily knocked up, surely the centre of a myriad of rumours about who the father of her baby was. She just hoped it never actually got out that it was her non-human teacher's bestial son growing inside her. A day of kinky sex and a child in exhange for a passing grade. She felt so dirty, so embarrassed, and yet she wasn't sure she was ashamed of it. Now that she was getting pumped full of magical beast sperm for a second time, pinned to a desktop and pushed to her limit, she was starting to think she might not be as vanilla as she'd once thought.

“Are you cumming again, my dear? You're so tight, I didn't think you could possibly clench anymore," Arvus grunted, leaning hard on her as his testicles drained out.

She hadn't even realised, but her own fluids were leaking against the centaur's solid shaft, getting trapped inside her with how hard he was pressed against her walls. He had impaled her, stuffed her, and in the end she enjoyed it.

“Yes...Yes..." she whispered in reply, her voice unable to get any louder as it felt like the last of her energy was draining away with her orgasm. It had been a long day, strapped under this stallion stud. Fucked through the halls and in front of her classmates without anyone even noticing. As her pleasure trailed off, and his steady stream of cum began to ebb, she let go of the straps binding her and slumped against his desk, gasping for air and for the first time considering how hot and sweaty she was. She was a mess, she felt used, but she had never been sexually satisfied like that before. She honestly wasn't sure what to think now, of her professor or of herself.

Student and teacher panted in unison from the day's exertion as Sabrina lay back on his sturdy desk and felt her lower body ache from the relentless abuse it had endured. He was softening now; even the impossible arousal of the stallion had its limits, and he began to withdraw from her sex with a wet, audible squelch through the ocean of semen he'd deposited within. As his huge dick popped free of her gape, she oozed his load all over the desk in chunky globs as he began to unfasten the straps holding the harness on to his underside.

With the desk supporting her back, the straps fell to her sides and the pressure that had been keeping her arms and legs wrapped around Arvus' belly vanished. Slumped on the table, the older male felt his shaft retreat back slowly into its floppy sheath as he stepped back from his student, gazing down at the damage he'd done to her well-fucked pussy with a wry smirk.

"You held up your end of the deal, my dear," he told her matter-of-factly, "and thus I will endeavour to alter your test records to reflect your... exemplary performance." She didn't look at him, gazing at the ceiling as her body adjusted to being back on solid ground and without two feet of horsecock stuffed inside it. The insistent warmth of his load didn't subside, however, and she took her time to enjoy the afterglow it provided.

"T... Thanks," she replied, before tilting her head down to gaze into his eyes. Despite all that he'd done to her, it had been her choice, and she knew it. Slowly sitting up, it was hard to ignore just how much of that thick semen was coating the top of his desk. "I... I can't believe we didn't get caught." Arvus grinned, crossing his arms and shaking his head.

"I wouldn't have risked it if I wasn't assured in my spells," he replied, "and now you shall pass the year, and I have enjoyed myself thoroughly. I do hope you won't let this interfere with your future studies; we still have many classes to go." She shook her head, groaning a little as she swung her legs over the edge of the desk and gingerly returned to her feet. A single flick of his wand, and she watched all of the exterior mess he'd made disappear from her skin instantaneously. Looking over at the door, Sabrina paused to retrieve her clothing from the floor to make herself more presentable.

"Back to your dorm?" Arvus inquired, as though he hadn't just ravaged her for an entire day, "do take care of yourself. You shall see your results... adjusted, in the next few days." She nodded, wiping the sweat from her brow, before hesitating.

"Is something the matter?"

"Do..." she began, looking back at her teacher, "do you think I could get some extra tutoring from you... if I need it?"

"I'll keep the harness in good condition, my dear."