Twin Tales 2

Chapter 1: The Device

The twins were absolutely, 100% “You damned kids better be listening!” definitely forbidden from playing in the Southern Ruins. But life for teenagers in a geological science outpost was D-U-L-L. Their parents were support engineers for scientists on a world far distant from Universal Commerce routes. Something in this planet’s mantle screwed with remote sensors, robots tended to go wonky, so it was boots-on-the-ground people in a temporary colony studying the planet.

There had once been an alien civilization here and for a while archaeologists had been part of the colony. But virtually no artefacts had survived the million-or-so years since the ancient civilization had died out or left their planet. So the archaeologists catalogued a few collapsed stone walls and bagged a couple of indecipherable coloured ceramic discs. Then they too departed for more interesting worlds.

The twins were Anthromorphs – hybrids of human and Dobermann dog. It was common for colonies to have Anthros of various mixed species – strength, heightened senses, quicker reflexes were some of the attributes the hybrids brought to a developing settlement. Oddly their adoptive parents had chosen engineering careers instead of the stereotypical security assignments Dobermanns usually perused. Like mules, hybrid species were sterile. Special bio-facilities developed hybrid babies which were then adopted out to compatible families.

Joshua and Kera were the only youths in the outpost. Their schooling was virtual, their friends were light-years away, and their parents were too busy to spend time with their offspring. When their training was complete the twins would be given the option to relocate to another planet or continue working in their parent’s colony. Joshua could hardly wait for the day when he could blow off this dustball planet.

Today, his sister was in the med-bay getting a sprained wrist treated, leaving Joshua to make trouble on his own. Outside the habitat was dust, rocks, and the distant Southern Ruins. Poking around crumbled walls and maybe finding one of those funky ceramic discs was too tempting to resist.

As a teenager Joshua was almost grown into his adult body. His pelt was mostly dark brown with mahogany highlights. His muzzle and paws were dark gold and he had a distinctive heart-shaped gold patch around his buttocks. While his ears were natural, curving down the side of his head, his tail had been cropped when he was an infant. The practice of cropping infants was frowned-upon. But his parents insisted shortened tails made life easier for Anthros to conform to human society. Joshua didn’t care – he could wear the latest human styles of clothes from the habitat fabricator. Because of the hot planetary climate the dog-boy rarely wore anything more than short trousers.

Joshua leaned his iCycle against a column of rock and climbed around the broken remains of a long-departed civilization. He imagined bustling streets full of Anthro dogs like him. The curious youth stooped to turn over rocks and peer into every crevice hoping to find one of the ceramic discs, or at least something other than dust.

Eventually he bored of his exploration and perched atop the rock column, tossing stones at other boulders to test his aim. Instead of the expected ‘clack’ sound of stone against boulder, one of the distant rocks made a deeper booming sound. Joshua was intrigued – something different on this homogenous world! He clambered down from his perch and sauntered to the otherwise unremarkable grey boulder. It looked like every other boulder but the impact from another tossed rock boomed hollowly. The curious boy circled the boulder peering in its shadow. There! A darker patch was a hole in the dust at the base of the boulder. Joshua excavated the dust with his hands, enlarging the hole. Suddenly the ground beneath his knees gave way and Joshua plunged into the dark with a cry.

Fortunately the fall was only a couple of metres onto a mound of sand that had filtered over the ages through the widened crack. Aside from bruised knees Joshua was unharmed. He stood and brushed dirt from his shorts. A shaft of bright sunlight filtered through dusty air, but the room was indistinct. Joshua activated the light on his wristwatch so he could explore. Aside from the hole in the ceiling the walls and floor were featureless grey. Brown dust was thick on the floor. Pacing the distance Joshua guessed the room was about four metres square and the ceiling about three metres high.

Aside from the blank walls and dust the only other feature of the room was an object on the floor at the centre. Cylindrical in shape and about 30 centimetres long the object resembled a large thermos flask lying on its side. Pearlescent metal showed through the dust in the wan torchlight. Joshua was amazed. He’d found a real-live alien artefact! Somehow he was going to have to smuggle the object home to show his sister. He squatted and brushed dust from the curved surface to reveal more of the iridescent metal. Something sharp jabbed is finger and Joshua yelped. A tiny bead of blood welled on his fingertip. He closely examined the surface of the artefact but couldn’t see any exposed metal splinters. Perhaps it had just been a shard of glassy rock. He sucked the blood away then attempted to pick up the object. He’d been expecting the object to be heavy – it hadn’t budged while he was brushing the dust off. But when he braced his legs either side, clasped the round surface and hauled upward the cylinder raised easily, almost weightless.

Joshua lost his balance and fell backward onto his butt, letting go of the cylinder. For a moment it seemed as if the artefact was hovering. But Joshua realized it was attached to a telescoping metal pole fixed to the floor. He had lifted the object to waist height and there it was now fixed. No matter how he pushed or strained against the object it remained immovable, supported at waist height by its pole.

Frustrated, the young man circled the object looking for a way to move it. Curiously the object looked slightly different from when he’d first discovered it. Joshua had been certain one end had tapered to a rounded cap, exactly like a thermos flask. But now there was no cap. Instead there was a small hole in the blunt end. No cap was visible on the floor – he didn’t think anything had fallen off the object. Joshua squatted to examine change. The hole was the diameter of his middle finger and surrounded by pinkish material. Experimentally the boy touched the pink surface. It yielded slightly to his finger and felt warm to the touch. While the surrounding metal was cold, this pink opening was warm. Cautiously Joshua pushed his finger into the hole. The material yielded easily then seemed to mould around his finger. It was warm and undulated slightly. For all the world it felt like someone was sucking on his finger. Joshua chuckled nervously. He was perplexed and fascinated. It was so weird to have this strange alien object sucking on his digits. Joshua pulled his finger out and checked it was fine, then put it back in. The sucking motions resumed. He withdrew his finger, stood up and stepped back.

The young man had only an indistinct understanding of sex. The OuterNet feed for the settlement was highly censored. Hybrids were grown in tanks, there was no need for them to ever engage in sex acts. Sex education for the young adults had essentially been: “Just don’t!” They were taught little more than the basics of their own biology.

Joshua had no inkling of the mechanics of sexual intercourse. Sometimes in the mornings his penis got hard and that made it difficult to pee. If he stroked his shaft it felt good and then his hardon would go away. But there was something enticing about the warm pink hole. It was exactly the right size to take his soft penis. And if the suckling had felt good against his finger perhaps it would feel good against his shaft.

Joshua’s thumbs hooked the elastic of his shorts and pulled the front down. He never bothered wearing underpants on hot days. The young man’s canine sheath was dark gold-coloured but hairless. Beneath, his scrotum was also hairless but black and shiny like satin. Using his fingers he pulled his sheath back a little to expose the tip of his penis proper. He leaned over the cylinder and manoeuvred until his penis touched the fleshy opening. It felt soft and warm on the tip of his penis. He thought maybe he should push in a little deeper, just to savour a little more. The finger-thin rod of his penis easily slipped into the orifice. It felt strange, but good, having the warm orifice surrounding his penis. He pushed deeper – all 15 centimetres of his shaft into the hole. The flesh of the orifice began the undulating, suckling motion he’d experienced on his finger. Around his penis it felt a hundred times better than on his finger.

Joshua closed his eyes, savouring the new sensations. He gripped the metal sides of the cylinder and pushed as deeply as he could trying to get as much of the suckling along his shaft as possible. Stimulation along his penis made his knot begin to swell as his shaft elongated and thickened. Joshua groaned with the unfamiliar sensations. For the first time in his life the young man’s knot was growing hard outside the protection of his sheath. But the warm tunnel of the artefact was so slick and soft that Joshua didn’t even realize. He closed his eyes and huffed, panting and gasping. The suckling on his penis was relentless and Joshua felt the good sensation building in his guts. It was like when he stroked himself but more tingly, more jolting. Unconsciously the teenager humped his hips as the tingling in his midriff grew. Something undeniable, something inevitable was building around his groin.

A sudden wave of overwhelming pleasure burst from Joshua’s groin. It seemed flash-bulbs exploded in his head, electricity jolted from his penis. His balls felt like they were bursting. He juddered against the artefact as a powerful orgasm wracked his body. Panicked by the intensity of the explosion of ecstasy Joshua tried pulling back from the machine.

But his swollen knot had locked him inside the fleshy hole. In fact the more he tried to pull back the more powerful the stimulation around his knot became and the orgasm crashed through his young body. The youth was trapped, shuddering as he orgasmed.

The device held him, clamped around the young man’s knot. It stroked and suckled him, prolonging the terrifying, wonderful sensations.

After an eternity the stroking relented and Joshua felt his knot softening. At last he could pull back, gasping as his penis slid free of the warm embrace. Tentatively, carefully, Joshua eased his shrunken knot back into his sheath. Every touch was over-stimulated and he gasped when his penis fully retreated into his sheath. He pulled up his trousers and stepped a pace away from the alien device.

His penis felt tender and his balls ached, but not in a bad way. He was so going to have to show the device to Kera!

Now, how to escape from the room? The hole in the ceiling was half a metre away when he stood on tiptoes on the sand hill. He couldn’t quite jump to reach the top edge of masonry where the chunk had fallen away. Frustrated, Joshua glared at the so-near-but-so-far freedom. Suddenly inspired he used his wristwatch to summon the iCycle he’d parked by the ruins. A few moments later the reassuring hum of the ‘cycle approached the hole. Gracefully it descended on grav-beams to rest on the mound next to Joshua. The ‘cycle wasn’t powerful enough to lift Joshua from the hole but he could balance standing on the seat and reach the edge of the cracked ceiling. He hoisted himself out of the hole followed by the hovering iCycle.

At dinner Joshua could barely contain his excitement. He whispered to his twin sister that he’d found something amazing but she wasn’t allowed to tell their parents or they’d both be in huge trouble. Tomorrow they had to go back to the ruins so she could see the… thing, whatever it was.

Two teenagers scooted their iCycles to the forbidden ruins on the following day. Kera was practically indistinguishable from her brother. Her markings were identical, she wore the same designer short pants and nothing else. Like a canine, she never developed breasts. Hybrids didn’t raise infants, so her nipples were un-developed like her brother’s. If you didn’t notice her muzzle was narrower than her brother’s and her features more finely drawn it was impossible to tell the two apart. Kera trusted Joshua absolutely so when he said he’d found something amazing she immediately shared his excitement.

The resourceful twins purloined a force-ladder from the engineering workshop so they could easily access the subterranean room. Joshua set a lantern hovering to illuminate the room fully. In the brighter light the walls of the room seemed less uniform grey. Gold and sapphire filaments were faintly visible in the stonework. The artefact was slightly different to how Joshua remembered. The diameter seemed larger. He remembered it being about 15 centimetres across, but now the diameter looked to be more than 20 centimetres. Perhaps he was just mis-remembering the size. There definitely hadn’t been a pink handle at the opposite end to the hole. But now a glistening pink rod about 15 centimetres long and 2 centimetres wide protruded from the end of the artefact. It seemed to be made of the same fleshy material as the hole.

Kera was captivated by the device. She exclaimed in excitement how they were going to be famous explorers, discoverers of this wondrous… thing! Joshua swore her to secrecy – if their parents found out they’d been exploring the Southern Ruins they would be grounded for life. Kera nodded solemnly – her brother was right, of course. This would have to be their secret. It was a small act of rebellion against their parents but that made their secret more thrilling.

Joshua demonstrated how the hole in the device could suckle on his finger and encouraged Kera to try. She giggled at the sensation like a mouth sucking. Slightly abashed Joshua explained how he put his penis in there and then the world seemed to explode.

Kera was fascinated, “What’s your penis look like? Show me!”

“You know… I guess it looks the same as yours.” Joshua waved vaguely at the front of Kera’s shorts.

Keba looked at the hole in the device, “I don’t think I have a penis I can put in there. You show me how you did it!”

For a moment Joshua was embarrassed. He hadn’t been naked in front of his sister since they were toddlers, “Oh, ah… okay. But you can’t laugh and if you tell anyone I’ll never speak to you again!” Reluctantly he lowered his shorts.

Kera watched, intrigued, “Oh! Your parts are different to mine!” She squatted to look closer at her twin’s sheath, “Can I touch it?”

“What? No! Eww!” Joshua used his hands to hide his sheath from his sister, “Just step back a bit and I’ll show you how the device works.” He dropped his shorts to the ground and stepped out of them, standing completely naked before his sister. He blushed with embarrassment and tried to ignore her stares. Using his fingers he pulled his sheath back a little, exposing the tip of his penis. He barely heard his sister’s quiet exclamation of “Wow! Neat!”

Again he carefully aligned the tip of his penis with the hole in the device, then he pushed his hips forward, “You gotta, ahhh… you gotta push real deep into the hole. Ooo! Ah… then it starts feeling… oof! It starts feeling really good…” Joshua gasped as the warm suckling began along the length of his shaft. Unconsciously he humped his hips as the device stimulated him. He clasped both hands around the cylindrical body of the device so he could push as deep as possible. “Oh… ah… it gets tight and … it feels like I need to pee real bad, but not like that… and… ah… and… oh… OH! Gaaah!” Joshua spasmed against the device. The tingling in his belly exploded into bright ecstasy. For the second time in his life Joshua experienced a juddering orgasm.

“Hey! Hey are you okay?” Kera was concerned, but didn’t want to interfere with her brother.

“Ahh! Yeah… yeah… it’s really good! Just… ahh, oh, just give me a few minutes, can you?” Somehow, despite appearing to be tortured, Kera’s brother was adamant he was enjoying the sensations. She nervously watched, intrigued but sceptical.

After a few minutes of her brother just leaning over the device and panting Kera asked, “Are you sure you’re okay? Should I pull you back?”

“No! Ah… no, you can’t.” Joshua blearily looked at his sister, “I’m kinda stuck here. My penis gets swollen and I can’t pull it out. Don’t worry, it goes away soon and then I can.” He lowered his head. Drool ran in a stream from his maw.

Kera became more and more distraught, “Josh, if you’re stuck I think I should go get Dad.”

Mention of his parents suddenly made Joshua’s enjoyment flee. His Dad would kill him for being in the ruins, for being naked in front of his sister, for playing with an alien device, and probably for doing things with his penis too. His knot shrank quickly away and his shaft slipped from the orifice. “Oof! Ah, see? It’s fine. I’m fine. You can’t tell Mum and Dad!” Carefully, under the watchful eyes of his sister, Joshua eased his penis into the protection of his sheath. Then he pulled his shorts up. “Really, Kera, that’s the best feeling in the world. You gotta try it, you really really have to try it too.”

Kera still looked sceptical, “You really sure it feels good?” Her brother nodded vigorously and grinned, “But I don’t have penis, like you. I can’t try it.”

Joshua looked crestfallen, “Sis, you gotta. It’s the best. And how do you pee if you don’t have a penis?”

“I pee from my girl bits, but they’re different to yours,” Kera explained.

“Show me!” said Joshua, “You saw my penis – it’s only fair I see yours.”

“Well… okay,” she lowered her shorts, “But you can’t laugh either, or tell anyone!”

Joshua was captivated. She had no penis at all! Instead, where the base of a sheath would be she had a mound of black flesh. It looked like three tiny pillows were pressed together to make a triangular bulge with a Y-shaped centre. The boy peered closely trying to decipher what he was observing, “Well, where does your pee come from?”

Kera blushed. With her fingertips she spread apart the two upper pillows of her vulva revealing the pink centre and the nub of her clitoris.

“Oh! You’ve got a hole there!” Joshua glanced back at the device, “Hey, maybe you can use the handle on the other end!”

Kera blinked. She noted how the pink rod glistened. It was about the same diameter and longer than her index finger. Cautiously she touched the fleshy material. The surface was warm and slick. A slight thrumming tickled her fingertips. Maybe it was made for girl bits.

“Well… okay. But just a bit, to try it out.” Kera cautiously approached the glistening rod until the blunt end touched her vulva. “Ooo! It tingles!” As she moved a little closer the tip of the rod pressed between the puffy lips. “Mmm… it’s warm and slippery. Oh! It’s moving!” The tip of the rod had curled upward slightly. “Okay, I can take it a bit deeper.” As Kera moved her hips forward the rod curved upward to align with her vagina. “Ooo, I can feel it in me. It’s humming. Mmmm…” She moved her hips closer to the device. 2 centimetres of the rod was in her vagina. She gave a sudden start, “Ow! Hey, that stung!”

Joshua looked on with sudden concern, “Uh, you wanna stop? It didn’t hurt me at all.”

Kera paused but the sting was fleeting. “Nah, ‘sokay. I think I went a bit fast. Feels really good now though.” Humming vibrations soothed her passage. The slick rod seemed perfectly made for her. Slowly Kera’s vulva moved along the rod which flexed to accommodate her. Her face was scrunched in concentration, prepared to move away if the device bit her again. She was determined to prove to her twin brother she could take anything he could. And it certainly felt nice.

When her vulva pressed against the base of the device Kera gasped. “Oh that feels really nice!” Unseen, a nub had grown on the top base of the shaft exactly the right position to press against her clitoris. Kera grasped both hands around the body of the artefact. Rotating her hips up and down made the nub stimulate her clitoris. “Ooo, it’s getting bigger! I can feel it swelling inside me!” Kera gasped and moaned. A bulbous swelling grew inside her, pressing her in delicious ways and vibrating. The nub at her clitoris became concave then latched suckling onto her clitoris. “Oh Josh, oh I can feel it! Like I gotta pee… Oh I gotta pee real bad!” Kera tried pulling away from the device, but the swollen knot held her firm. “Eep! I’m stuck! Oh no… I’m gonna… I’m gonna… Oooooooo!”

Joshua was beginning to panic. His sister shouldn’t be stuck on the rod and she sounded like she was in pain, “Sis! Is it hurting again? What should I do!”

Kera convulsed against the device, gasping and moaning, “Nah, nah don’t stop! Ooo yeah, that’s so good!” She threw her head back, moaning. “It’s like waves… Inside me. Oh here it goes again! Oooo, that’s so nice!” She dropped her head forward. Drool ran from her muzzle.

Her brother hopped from foot to foot, trying to keep his panic at bay. Had he acted like that when the device made him feel good? Joshua voice trembled in panic, “Sis, you should stop now. I don’t think we should mess with it anymore!” He put a shaking hand on her shoulder.

Kera lifted her head with a start, “No! Oh… give me a bit longer, ‘kay? It feels so good. Nyaa, it’s pressing inside me and vibrating and ooo I’m gonna go again!” She drew a deep shuddering breath, letting it out in a moan.

Joshua sat on the broken slab, shaking. He was really frightened for his sister. Should he run to get help? It seemed the device had trapped his sister forever.

Eventually Kera pulled away. The slender rod slipped effortlessly from her vagina. A tiny smear of blood streaked the surface of the rod. Even that vanished, absorbed by the fleshy material. Kera pulled her shorts on and sat next to her brother. She hugged him. “Josh, I’m fine. See? Not hurt at all! You were right, that feels so nice! I’m really glad you showed me. It was a good feeling!”

The young man’s concerns eased a little, “You sure? You looked like you were dying! I was so worried!”

Kera gave him another reassuring hug, “It was great! But we’d better get back home before lunch.”

The twins elevated out of the room and iCycled back to the habitats. The fear was gone, they laughed and joked about their new plaything on the way home.

Chapter 2: Shared Experience

The next morning two dervishes wolfed down their breakfast, shouted to their parents they had to go dust-rat hunting, and hurtled out the door. Frantically they ‘cycled to the ruins, racing to see who could get there first. Kera passed the stone column in the lead but Joshua leapt off his ‘cycle, slamming it down and sprinted to the hole. They argued who had won and what the rules actually were.

They were still arguing as they dropped into the room. Without embarrassment both youths removed their shorts and approached the alien device.

“I should go first, because you took forever yesterday!” Joshua declared.

“Na, uh. I won the race and anyway I’m older than you!” Kera argued.

Joshua pouted, “You’re only older by a few minutes.” He hated when his sister pretended she was more adult.

Kera looked at the device. “Oh! We can go at the same time! You go on that end and I go on this end.” She pointed at the respective fittings.

“Yeah! Cool!” Joshua brightened, “Last one on is a smelly rat!” But he cautiously pulled his sheath back and poked his penis into the hole. At the same time Kera manoeuvred her hips so the slimy rod penetrated her smoothly. They were both looking down at the device in concentration and bumped their heads together, laughing. Their chests were almost touching.

Simultaneously the twins gasped. Warm suckling played along Joshua’s penis while the rod inside Kera hummed and flexed. “Ooh, Joshua this is a good plan! Mmmm…” Kera moaned out.

Awkwardly both teenagers tried to grasp the body of the device for more leverage to hump for stimulation. They realized they could brace their hands against the other’s shoulders and synchronize their humping. Somehow that made the feelings even more intense. Simultaneously the twins cried out, “Oh Josh/Kera! I’m gonna go!”

Joshua’s knot was swelled inside the fleshy tunnel, holding him fast while undulations and vibrations stroked his penis. Kera was likewise held firm by the bulge in her vagina. A fleshy nub suckled and rubbed her clitoris.

Beneath Joshua’s penis a small shelf extruded from the device. The shelf curled upward, cupping Joshua’s scrotum. It moulded to conform around his balls. The young man was so lost in the throes of his climax he barely registered the additional stroking sensation around his scrotum. If anything the sensation of a soft tongue stroking his balls made Joshua orgasm even harder.

The twins writhed and convulsed, stimulated to orgasm by the strange object. They moaned and thrashed, clasping tightly onto their sibling. As the intensity of their initial orgasm tapered both teenagers dropped their heads forward to rest on the shoulder of the other. Unconsciously each sibling drooled saliva down the back of the other. They rested together, occasionally juddering and shaking as another jolt of electric pleasure gripped them.

At the same time as Joshua’s knot began to shrink Kera felt the pressure inside her receding. They raised their heads and pulled away from each other. Kera gasped as the rod slipped free at the same time Joshua gasped when his over-stimulated penis retracted into his sheath.

Exhausted, the twins sat with bare buttocks on the warmed slab. They hugged and chuckled softly. Each declared that was the best sensation they’d ever felt.

Beeps, whistles and grunts seemed to be coming from the alien device. Joshua raised his wristwatch, “Oh hey, Ciril, translate this.”

“Translating…,” came the reply, “Translation failed. Please collect more training data.”

“Bah. Probably just said, ‘Don’t forget to wash your hands’ or something” Joshua giggled and his sister joined in.

“Don’t forget to wash your hands.” Kera deepened her voice, to imitate her gruff father. Joshua screamed in laughter and rolled back naked on the slab. Kera rolled next to him.

“Hey, look! The ceiling is really pretty!” Kera looked up in wonder, “I just noticed. The walls too!”

Around them gold and sapphire filaments in the darker grey walls glinted. Joshua was sure they hadn’t been that bright yesterday. He sat up looking closer. Faint glints of light seemed to race along each thread, dividing at the intersections and racing in another direction. It was quite beautiful.

“Oh shit!” Kera suddenly looked at her wristwatch, “It’s almost lunchtime! We’d better get back quick before Mum and Dad get home!”

The twins threw on their shorts and elevated through the ceiling. They shouted and laughed as they each tried to race the other home on their iCycles.

Chapter 3: Developments

When the twins descended into the room the next day the device had altered. Each end still looked the same – there was a fleshy hole in one end and a glistening rod at the other. But half way along the device a lattice of light-grey pipes and tubes had woven a small barrier. Near the device the barrier was narrow but toward the height of the twin’s chests it fanned wider. Joshua poked the woven pipes which wobbled slightly. “Should we… should we still go on the device?” he was cautious about the way the artefact was changing.

Kera dismissed his concern, “Yeah, that wont get in the way. It’ll just be flat between us. Anyway I really do want to go again!” she was already dropping her shorts to align with the appendage which pleasured her so profoundly. She thought for a moment the rod was slightly thicker than yesterday, and maybe a bit longer. Her cropped tail waggled in anticipation.

Her brother shrugged and discarded his own pants into the dust – Joshua also couldn’t wait to feel that clasping warmth again.

Without preamble the twins mounted their respective ends of the device. Joshua fed the tip of his penis into the waiting hole while Kera slid along the length of the rod. They knocked their heads together again and chuckled. Between them the fan of tubes was about half the width of their chests. Eagerly they braced their arms together so they could hump the machine in unison.

As before the device suckled and hummed, throbbed and stimulated the cubs. Joshua’s knot and the swelling in Kera locked them together. Joshua was aware of a tongue-like extrusion licking his balls and it felt divine. The teenagers cried out together as they were simultaneously brought to yet another crashing orgasm. They fell forward, embracing with their heads resting on each other’s shoulder.

Between them the tangle of pipes unravelled. Eight pipes in two vertical rows of four extended toward each pup. Every pipe grew a tiny suction cup. Gently the pipes latched onto each of pups’ eight canine nipples. The twins raised their heads, blearily peering at the other’s chest to see the pipes connected to their sibling. But when the suckling and vibrating tubes massaged their sensitive areolas they both slumped forward. The added stimulation prolonged their bliss, taking both youths to greater heights of ecstasy. They juddered and shook, wracked with waves of orgasm.

After an interminable period the waves of pleasure ebbed away. Joshua’s deflated knot slipped from the warm orifice. A watery dribble of fluid dripped from the hole, and clear liquid dripped from the tip of his penis as it retracted to his sheath. In a haze the boy wondered briefly if he had peed into the hole.

As Kera drew back she gasped. The rod was definitely thicker and left her feeling hollow when it withdrew.

The two exhausted pups collapsed next to each other, naked on the warm slab. They hugged together, silent but happy in the afterglow of their shared bliss. Two stubby tails wagged slowly in happiness. The device blipped, grunted and burbled. “Don’t forget to wash your hands!” grumbled Joshua in a gruff voice. The twins laughed.

“Translating… Translation failed…” The voice from Joshua’s watch declared into the room.

Kera rolled over to look at her brother, “Hey, your nipples are red,” She looked down at her own chest, “Oh! So are mine.” She rubbed her chest and gasped. Her nipples were sensitive, but in a good way. “Hey! Your boy bits look different too, I think.”

Joshua sat up with a fright, “What? How!” He pawed at his groin.

“Silly, move your hands so I can look,” Kera peered closely at her brother’s groin, “Yeah! The thing… the bag under your penis is bigger. And I think your penis is bigger too.” She reached forward to touch Joshua’s scrotum.

The boy flinched, but then his sister’s caress felt good along his velvet sack.

“What’s that for, why do boys have that bag?” she asked, curious and exploring his balls. She experimentally squeezed one between her fingers.

“Ow! Hey! Don’t squash them – that hurts!” Joshua scooted back out of her reach.

Kera was absolutely contrite, “Sorry, sorry sorry! They felt like marbles – I thought they would be hard. So what’re they do?”

Joshua shrugged, cradling his sore balls, “Dunno. I think pee comes out of them or something.”

Kera looked dubious, “I don’t have a bag like that, and I pee. Oh! My bits are different too!” She hunched forward, trying to look at her vulva. “I think it’s bigger too.”

Her brother peered over, “Move your head. Get your fingers out of the way,” he crawled forward with his chin almost scraping the slab and stared at his sister’s vulva. The three small pillows were definitely larger and her mound was puffed up. He traced a finger around the lips, “Yeah, you’re bigger and puffier. Does this hurt?” He pressed a finger into the cleft of her vulva. Kera juddered, and Joshua quickly pulled his hand back, “Sorry, sorry!”

“No, that felt really good, like the device,” she reassured him. It had felt nice having her brother touching her down there. “Oh shit! We’re late for lunch again!” Keba leaped to her feet, grabbing randomly one of the pairs of shorts. She hopped from foot to foot, donning the pants while her brother did the same. The two young adults vanished in a whirlwind of dust and laughter, racing homeward.

Chapter 4: Intrusion

The device had changed again by next morning. The body of the machine had grown fatter to accommodate a larger orifice at Joshua’s end. The rod on Kera’s end was almost 15 centimetres long and round as her thumb.

Around the walls of the room bright sparks raced along the gold and sapphire tracks. The lights detonated with a tiny flash as they divided into other stars at the intersections, before firing along their new filaments. While it was supremely pretty, obtaining the pleasures of the artefact was the focus of the twin’s attention. Each time they’d used the machine the pleasure it brought was greater than the previous time. Each orgasm was more powerful than the last.

They each hastily threw off their pants and scrambled to the machine. Joshua’s sheath was definitely larger and his scrotum swung beneath. As he aligned his penis he noted how much thicker and longer his exposed length had become. The device’s larger hole was still perfectly suited to his member has he pushed inside. Fully 17 centimetres of his shaft pressed into the orifice.

At the other end of the device, Keba sighed as the thicker rod curved up into her vagina, pressing in delightful ways. The youths embraced, synchronizing their humping hips. Their chests pressed against the web of tubes which unfurled and latched onto their respective nipples. In moments both cubs were gasping and crying out as incandescent pleasure jolted their bodies.

At the crescendo of their orgasms the two young adults felt a new sensation. At the tip of Joshua’s penis a tiny probe had entered the opening of his urethra. It was thin, soft, and he barely felt the probe sliding inside his urethra. Whenever the new sensation distracted him, a corresponding flurry of vibrating suckling along his shaft and nipples wrenched his focus back onto the pounding orgasm.

Inside Kera’s vagina the throbbing shaft grew a twined pair of probes from the tip. The slender shafts penetrated her cervix, snaking along her uterus. The girl gasped, feeling something unfamiliarly intimate in her womb. But the larger shaft throbbed and swelled, undulating in a sensual way. She closed her eyes and let the bliss wash her momentary concerns away.

Somewhere in Kera’s fallopian tubes tiny nanoscale filaments writhed toward her ovaries, industriously working.

Somewhere in Joshua’s vas deferens tiny nanoscale filaments writhed toward his testes, industriously working.

Oblivious to anything but a tsunami of bliss the twins embraced each other, lost in the shared ecstasy. Unconsciously Kera kissed the muzzle of her brother. Without thinking the boy reciprocated. Somehow pressing their muzzles together made the orgasm even more powerful and longer-lasting.

At times Joshua felt liquid squirting from the tip of his penis, synchronized to the most powerful washes of pleasure.

Un-noticed and unfelt the internal filaments withdrew from the two bodies.

An eternity later the twins separated as the device released them. Joshua noticed a rivulet of milky-white fluid drain from the orifice as he drew his penis free. It took both hands to ease his shaft into his larger sheath and the same milky-white fluid dripped into the dust.

Kera was amazed as 17 centimetres of thick rod slid out of her vagina as she pulled back. That was definitely larger than when it went in. But oh, that stretchy sensation was just heavenly.

The twins collapsed on the warm slab, exhausted. They hugged their naked bodies together, tails wagging happily.

“Joshie, that was the best yet!” Kera sighed.

Joshua lay next to her with his eyes closed, still basking in the afterglow of his orgasm. “Mmm, yeah. Hey, did you feel something kinda different, like weird inside?”

Kera sat up, “Yeah, like something touching me in here.” She indicated near her kidneys.

Her brother sat up next to her, “No, it was something down here.” He tentatively grasped his larger scrotum, “It felt a bit like when you squeezed me down there, but not so hurty. It wasn’t painful, just… a bit strange.”

Kera shrugged. “Maybe the machine was making your bag bigger. And it got lost looking for mine.” She giggled.

At the centre of the room the artefact blooped and buzzed, with a whistle.

Kera scowled at Joshua, “Don’t you say anything!”

Joshua put on his most serious face, and made hand-washing motions. Kera shrieked with laughter and the two adolescents rolled on the slab, wrestling.

“Translating… Unknown, ‘third’, unknown, ‘return tomorrow’ unknown. Please collect more training data.” Joshua’s watch murmured from beneath his sister.

Chapter 5: Intrusion 2

Beneath either end of the device hung curved pipes. The shafts appeared to be made of the same pink, fleshy material of the other appendages. Joshua peered curiously at the glistening tubes, then shrugged. It didn’t look like the pipes would get in the way of their fun.

With a rushed breakfast and a shouted departure message about dust-rats the twins bolted from the house. They had ignored their mother’s admonition about changing their filthy shorts as they rocketed past. The siblings were eager to return to their plaything in the glittering room.

Before their feet had even touched the slab the twins tore off their shorts, tossing them to the dirt. They barely paused to acknowledge the changes on the artefact. A new appendage on the toy didn’t quell their enthusiasm to experience the colossal bliss the device brought each day. They anticipated even greater bliss every day. Any concerns about the invasive probes from yesterday were discarded with their clothes.

Joshua peeled his thick sheath back and pressed forward into the soft orifice. He sighed in pleasure at the familiar embrace around his penis. His legs straddled either side of the pipe that curved from beneath the machine to behind him. But the pipe was warm and soft and didn’t interfere with his penetration. Beneath his scrotum the tongue-like extrusion stroked his balls.

Kera slid forward on the thickened rod at her end of the device. It curved delightfully upward, perfectly matching her forward progress. When her vulva pressed against the base of the rod she sighed. The rod thickened as the wondrous bulge filled her vagina. Likewise she had to straddle the curved pipe between her legs. It was odd, but when she was nestled full depth with a suckling nub on her clitoris she forgot about the new attachment.

Once again the machine hummed, throbbed, and suckled to life. The twins embraced against the web of pipes as the suction began on their under-developed nipples. In slowly building waves the artefact brought the twins closer to orgasm. They humped the device until Joshua’s knot and the bulge inside Kera prevented them from being able to move their hips. Automatically the twins locked their muzzles together – kissing passionately seemed natural, heightening their experience.

They paused their kissing briefly to both throw back their heads and shriek as a cascade of pleasure erupted in their groins. Incandescent fire poured into their bodies, making them writhe against the device. The twins kissed again, moaning into the other’s mouth in shared bliss. Their arms were wrapped around each other, hugging their twin against the web of tubes suckling their nipples.

Between their legs the new pipes curled upward. Behind both youths the tubes quested for a moment, stroking over the heart-shaped bronze patch of their rumps. The blunt ends of the pipes nestled under the stubby tails of the twins, resting against their puckered anuses. With their orgasms building, neither of them noticed nor cared about something pressing their butt-holes.

Together the youngsters cried out as their orgasms crashed into them. Synchronized to the relaxation of their sphincters between waves, the new rods surged forward. The tapered shafts speared into the anuses of the teenagers. The twins yipped in surprise at the intrusion, but the warm fleshy tubes vibrated and thrummed in their depths. The material was soft, pliant and not uncomfortable. As the tubes wriggled deeper into the youngsters, the suction on their nipples increased, the vibrating throbs of the suckling orifice around Joshua and the swollen knot in Kera amplified their stimulation. The twins cried out together in overwhelming bliss. Their young bodies spasmed and juddered through their orgasms.

At the same time the invasive probes slithered into Joshua’s urethra, and through Kera’s cervix. The nano-scale tools worked inscrutable adaptations inside the twins.

In the rectum of each youngster a writhing shaft of flesh wriggled deeper. The tube undulated, swelling and receding, questing around the intestines of the oblivious couple. The humming vibrations stimulated something inside Joshua that made his penis jolt in fantastic ways. Somewhere deep in their guts fiery liquid poured from the end of the tube. With spurts, each sibling felt as though sunshine was flooding their abdomen. The heat radiated outward, filling their chest and groin with tingling warmth. Then it spread to their limbs and head, suffusing them with glowing happiness. The twins groaned through their kisses, lost in a maelstrom of ecstasy.

Time was gone, sensibility was gone. The twins clung to each other in desperate pleasure.

Several times as the peaks of orgasm shook him Joshua felt jets of liquid spurt from his penis. The tongue-like device licking his scrotum flexed each time his balls drew up in release. The pleasure was almost unbearable.

At Kera’s peaks her vaginal muscles clamped around the knotted shaft inside her. It tugged her internally in delicious ways as she orgasmed. It felt like her body was trying to milk the fleshy appendage.

But as before the pleasure drained way in slow waves. With the departing tide nano-scale probes withdrew. The long, fleshy tube slithered out of their butts and withdrew beneath the artefact. As the tip popped free the cubs clamped their tails down. Even as Joshua’s knot deflated, and Kera was released from the swollen bulb the twins stayed embraced, kissing. Their passion for each other lingered for a while after the last of the stimulation was gone.

Something dribbled down Joshua’s scrotum and he pulled back. When he withdrew his penis from the device a flood of whitish liquid cascaded to the floor. It certainly didn’t look like pee. Maybe that’s what his balls were for.

Drained, the adolescents cuddled together on the slab. Their muzzles pressed together again softly, without their earlier fiery passion. It somehow felt completely right to both of them. They were silent as they basked in the warm afterglow of their shared experience. When the machine beeped and chirped the twins ignored it.

When they broke the kiss Kera asked, “Hey Joshie, did something go in your butt this time?”

Joshua could still feel slickness under his tail, “Yeah, it was really weird. Didn’t hurt though. I think it squirted something in me that felt really good.”

“Yeah, me too…”

“Translating…” interrupted Joshua’s wristwatch, “Unknown, ‘fourth’ unknown, ‘hormones completed successfully.’ unknown, ‘return tomorrow for next’ unknown. Please collect more training data.”

Chapter 6: Coupled

Kera was wearing a loose tee-shirt tucked into her shorts when she came down for breakfast. Joshua nudged her with his elbow, but she whispered, “I’ll tell ya later.” Their parents didn’t notice or comment as the twins departed on their daily adventures.

When they arrived at the ruins and parked the iCycles, Kera removed her tee-shirt.

“Woah! Your chest got fat!” exclaimed Joshua. His paw stroked over Kera’s more developed breasts, making her gasp. Yesterday her chest and abdomen had looked the same as her brother’s. Today Kera had eights developing breasts. The two topmost breasts on her chest were small mounds and as they progressed down her abdomen each pair was slightly smaller. The two nipples just above her pubic mound were barely changed.

“I know. You cant tell Mum and Dad!” Kera warned, “… but… that stroking feels nice. I like that.”

When the twins descended into the sparkling room the machine was completely changed. Instead of the cylinder with appendages at either end, a simple illuminated display perched on the telescoped stand. On the screen a stylized animation showed two anthro canine characters laying down. One of the figures was laying on top of the other. The display beeped and hummed.

“I don’t get it,” said Joshua, peering at the display with disappointment, “Where did the fun bits go? Does it want me to lie on top of you?”

The animation changed, zooming in to the groin of the figures. A stylized penis inserted into a representation of a canine vulva. The groin of the female figure changed to show an internal view. A knot formed on the stylized penis. Then the display returned to the original animation of the characters laying down. Whistles, pops and grunts came from the machine.

“Translating…” began the familiar voice of Joshua’s wristwatch, “’Please’ unknown, ‘natural position for’, unknown, ‘with penis in vagina is far superior’, unknown, unknown ‘to completion each day. Return tomorrow for’ unknown. Translation incomplete. Please collect more data.”

“Oh! It wants you to put your boy thingy in my girl bits!” exclaimed Kera, “We should try that!” She discarded her shorts and lay back on the slab.

“I guess that makes sense,” agreed Joshua, “Are you sure you want my penis to go in you?” He removed his shorts and crawled along the slab toward his prone sister.

She nodded vigorously, “Yeah, yeah! Maybe your penis will feel as good as the machine did!” Kera spread her legs so her brother could crawl between.

Laid out naked on the stone she looked beautiful. Her dark pelt contrasted the light cement. A shaft of sunlight made silver highlights on her shiny fur.

Joshua didn’t have the words to express how he was feeling, admiring her silky black and bronze canine body. He small breasts looked soft, like he could nuzzle them. Her vulva puffed out and the Y-shaped crevice seemed to call to him. “You look uh, pretty, sis.” The words seemed silly to his ears.

Kera grinned, “You look, umm, pretty too.” Their unfamiliar vocabulary couldn’t encompass how they felt toward each other. “I like looking at, uh, where you hide your penis, and the bag underneath is all soft. I really want to feel your penis inside me!”

Awkwardly Joshua tried to align his shaft with her entrance as he knelt between Kera’s legs. He couldn’t seem to crouch low enough or get the angle right. Both twins grumbled in frustration. Kera had the idea to scoot her butt close to the edge of the slab with her legs over the side. Joshua knelt on the dust mound a bit lower and his penis aligned perfectly with his sister’s vulva.

With trial and error and a wince of pain from Kera, the boy adjusted the angle of his entry. His penis bone separated the three pillows of her vulva and he speared into his sister. Both twins gasped as Joshua’s scrotum touched below Kera’s vulva.

Joshua’s penis was fully inside his sister and it felt way better than the machine. She was warmer and more alive. Her flesh clenched in a natural way around him. And she was his sister – that somehow made the feeling even better. The boy grinned down at his sibling.

Likewise, Kera felt her brother’s shaft was more intimate and more alive inside her than the machine. She grinned up at her brother, “We’re doing it! Can, uh, can you hump me like you did with the hole? It’s hard for me to move properly, laying down.”

“Uh, sure!” Joshua moved his hips back then pushed forward again. Her slick passage sliding along his penis felt amazing.

“Ooooh, yeah, just like that.” Kera gasped, “Keep doing that, harder though!”

The boy leaned forward to put one hand either side of Kera’s chest and pushed his legs out behind him like the characters in the display had shown. In that position Joshua was able to pump his hips forward and back more quickly and with more force. When he impacted his hips against hers his scrotum slapped beneath her vulva. With the rhythmic stimulation of her vagina rubbing along his penis Joshua could feel his knot beginning to grow. He grunted with each impact.

Kera was in heaven. She could feel the thickening shaft of her brother elongating, rubbing her deeper with every thrust. His growing knot repeatedly spread her vulva lips and pressed delightfully against her clitoris. She reached her arms to clasp her brother’s hips, encouraging him to pump harder and faster. Something profound was building in her abdomen and she wanted more of it.

When the boy’s knot engorged too large to withdraw the boy lost all volition. Instinctively Joshua hammered his hips against his sister in short rapid strokes, tugging the knot inside her but unable to withdraw. Each forward push ground his pubis against his sister’s vulva, compressing the flesh against her clitoris, stimulating her toward orgasm. He also felt the profound sensation building in his abdomen. He was getting close to cumming inside his sister.

As one the twins cried out. Joshua’s knot pulsed in the tight space. His balls pulled upward and with a cry he squirted his semen into his sister. Kera felt the pointed tip of her brother’s penis pressed hard against something deep inside her. Hot liquid spurted into her, passing some constriction to flood her. The machine had never done this, but it felt amazing; so right and so good.

Electric jolts of orgasm tore through the young lovers. Each spasm tugged the knot lodged in Kera’s depths, stimulating them both to greater heights. Like the first time Joshua had used the machine, bright lights flashed in his mind, his ears roared, and bliss poured through him. He pumped load after load of semen into his sister’s womb. Kera moaned a long, drawn out cry as her orgasm peaked in waves. Her clenching vagina wanted to milk every drop from her brother’s penis.

Joshua was lost in bliss. The feeling of ejaculating in his sister was orders of magnitude better than the machine. He was inside the body of the girl he adored, filling her with his essence, sharing his experience with her. He was making her feel as good as she was making him feel.

He could no longer support his weight with his arms, so lay on top of his sister with his knot still buried and spurting inside her. Kera hugged her arms around her brother, both in affection but also to keep his pubic bone grinding against her clitoris. She rotated her hips forward and back slightly, tugging at Joshua’s knot and rubbing him against her. Joshua spurted jets of liquid until he felt his balls were being wrung out. Both twins grunted and gasped with the ebb and flow of their bliss. In their shared passion they joined their muzzles in a deep kiss.

They stayed like that – locked together with the boy laying on his sister for half an hour. Each time the intensity of their bliss began to fade one of the twins would have to shift slightly. The movements tugged against their union, stimulating them both toward another peak of release. Together they groaned in pleasure, then returned to their passionate kiss.

Chapter 7: Something different

At breakfast the twins were wearing matching shirts tucked into their filthy shorts. Their mother commented that at least the twins had found something decent to wear. Kera elbowed her brother, silently asking why he wore a shirt. Joshua elbowed her in return but stayed silent.

They both removed their shirts and pants where they parked their ‘cycles at the ruins. Kera peered at her brother’s chest, “It looks the same! Why did you have a shirt on?”

“Because I like dressing the same as you!” the boy smiled at his sister, “And anyway Mum would get suspicious if only you wore shirts. Hey, your chest is even fatter today!” Kera’s breasts were slightly rounder than they had been yesterday. Each pair had developed just a little. Even the two smaller nipples close to her vulva were larger, and perched on a small mound. “Can I touch them again?”

“Sure! I liked you stroking them,” Kera said.

Joshua tentatively ran his fingers around the bulges on Kera’s chest. The fur was powdery soft on the mounds. Her nipples had grown a little more plump, a little more prominent. She gasped when the boy’s fingers traced around her nipple and gently squeezed. A small jolt of the good feeling twanged inside her.

“That feels really good. You can do that more,” she encouraged her brother.

Without thinking, Joshua nuzzled his face against the soft mound of his sister’s breast. He breathed in the warm smell of her, feeling the delicate fur against his face. Encouraged by his sister’s soft moaning he moved his lips, kissing her breast. On impulse his tongue flicked out, licking around her areola. Each touch brought another gasp from his sister. His tongue formed a seal around her nipple to the top of his maw and he suckled like a baby while his fingers explored her other nipples. He moved from one nipple to the next, licking and suckling until he was kneeling in front of her, tonguing the smaller breasts near her vulva. Kera’s scent was stronger here and his attuned canine nose followed the source of her scent to her vulva. Instinctively he licked over the three pillows of her labia.

Kera gasped at the sudden jolt in her nethers, “Oh! Yes, do that again!” She spread her legs wider to give her brother easier access to her genitals.

Using his thumbs, Joshua spread the dark flesh of her two upper vulva lips to reveal the soft, pink flesh between. The delicious smell was coming from the deeper cleft. With his long canine tongue Joshua pushed inwards, seeking the source of her taste.

The young woman gasped and moaned as her brother’s tongue snaked into her vagina. Her knees almost buckled at the intensity of the pleasure sparkling in her belly. She grasped both hands around Joshua’s head, encouraging him to do more. Each time his lapping tongue extended full depth into her the base of his tongue rubbed hard against her clitoris. Involuntarily her hips pushed forward so she was riding his tongue like she rode the shaft of the machine. “Oh Josh… oh Josh… I’m gonna… it’s gonna…” The jolting pleasure was building to a crescendo. Her fingers dug into the sides of her brother’s head, scrunching his ears. With a loud squeal Kera orgasmed. Her vaginal muscles clamped around Joshua’s tongue, holding him inside her for a moment. She mashed her hips against his muzzle to press her vulva and clitoris against his top lip. It was all she could do to remain standing as the pleasure washed through her. Her body writhed in pleasure.

Joshua sustained her for as long as he could, but his knees were getting sore and he couldn’t breathe properly with her pubis mashed against his nose. He withdrew his tongue and sat back on a boulder.

Kera was panting, seemingly barely able to stand, “Oh Joshie… that was really really nice. Wow, you made me feel so good!” She leaned down to kiss him, tasting herself on his muzzle. “Hey, can I try to make you feel like that?”

“Umm… sure, I guess. I don’t have chests like you though.” He lay back on the boulder, naked in the sunshine.

For a moment Kera admired her brother’s naked form. His maturing body had developed ridges of muscles rippling his abdomen, his sheath had grown more plump over the few days. Beneath the bronze tube of flesh his scrotum had grown larger. It hung low, shiny and black with plum-sized balls inside. She leaned over him and kissed him again, savouring her own taste on his tongue. Then her kisses travelled down his neck onto his chest. She licked and suckled her brother’s upper set of nipples, tweaking the lower nipples with her fingertips.

“Oh! Mmm, yeah that does feel real nice,” Joshua wriggled on the boulder.

Her kisses progressed lower until Kera was suckling on the nipples either side of her brother’s sheath. With one hand she gently cupped the young man’s scrotum, carefully feeling the larger balls. She felt him flinch then relax as he realized she’d learned not to squeeze his balls. His scent was warm in the sunshine, earthy and masculine. Kera nuzzled her face against the velvet-soft skin of his scrotum and sheath, breathing him in.

In front of her nose a pink tip peeked from the opening of her brother’s sheath. Clear fluid dribbled from the round opening at the apex of the shaft. It didn’t look or smell to Kera like pee. Tentatively she extended her tongue to sample the liquid.

Joshua gasped at the touch of his sister’s tongue on the exposed flesh of his penis. An electric jolt of pleasure burst in his midriff as a small jet of fluid squirted onto his sister’s tongue. She pulled back abruptly at the unexpected release. The splash of liquid was a greater quantity than the small taste she’d tried for.

“Oh, that was really good. Can you do that again?” Joshua pleaded, hoping she wasn’t disgusted by the taste.

The girl smacked her lips, savouring the taste of her brother. It wasn’t bad, really. Just… different – slightly salty and a bit sweet. It was more the surprise of it squirting into her muzzle that had made her draw suddenly back. With infinite care and delicate fingers Kera slowly drew back her brother’s sheath, exposing more of his penis proper. Pink flesh glistened wetly in the sunlight. His masculine scent grew stronger the more of his penis she exposed.

On the boulder Joshua gasped and writhed at feeling Kera peeling back his sheath. He spread his legs, and his fingers clawed at the rock.

Cautiously the girl licked her tongue along the pink shaft. Her brother’s body jolted beneath her and another squirt of clear fluid arced from the tip of his penis to land on his chest. He drew in a sharp breath and begged her to do more. With one hand Kera held her brother’s sheath back so his exposed penis jutted upward. With the other hand she caressed his scrotum, stroking the velvet flesh. She leaned down and kissed the top of her brother’s penis. More clear liquid jetted into her muzzle. Kera swallowed it down, enjoying the taste.

In her mind she pictured how her vulva had enveloped and slid along the shaft of the machine. Perhaps she could do the same with her mouth along her brother’s shaft. Wrapping her canine tongue around the shaft, she could press her brother’s penis against the roof of her mouth. She lowered her head and took the length of his shaft into her mouth.

The boy writhed and gasped, moaning at the sensation of his sister’s muzzle. When her teeth accidentally grazed the sensitive flesh he yipped and cried out, “Ow! No teeth! No teeth!”

Kera drew back, mortified that she’d hurt her brother, “Sorry sorry! Do you want me to stop?” She knelt between his legs and put her hands on his thighs, rubbing gently.

“No! No… please don’t stop. It was great, but… you gotta be really careful about those teeth, ‘kay?” Joshua had been getting closer to the good feeling and hoped his sister would continue sucking his penis.

Near the base of Joshua’s exposed shaft a bulge was growing in her hand. For a moment Kera marvelled in disbelieving awe at his swollen knot. The bulge was as large as her clenched fist. Somehow yesterday that monstrous knot had been inside her, locking the twins together. Carefully she lowered her head, wrapping her tongue around his penis again. His shaft was getting thicker and longer in her mouth as she moved her head back and forth along his length. She was able to take most of his length in her mouth. Kera could hear her brother making those delightful moans when his body writhed. Every so often she swallowed his clear fluids down. The scent of him was powerful in her nose.

“Oh Kera… that feeling… it’s gonna come out… I’m… it’s coming…” Joshua unconsciously pushed his hips forward as the pressure in his balls grew unbearable. Her mouth along his penis felt almost like the machine, suckling and rubbing. Her fingers were clasped behind his swollen knot hastening the boy toward his release. “Ohhhhh SHIT!” He spasmed on the rock as orgasm burst into his groin. With a mighty clench his balls drew up and a torrent of liquid hosed from his penis into his sister’s mouth. Distantly he could hear Kera struggling to drink the voluminous ejaculation down, swallowing mouthfuls. He was lost in bliss, pumping a firehose of his essence into Kera’s suckling maw.

The flow was all Kera could do to swallow. Whitish dribbles escaped from the sides of her muzzle and poured over her paw grasping her brother’s knot. The taste was stronger but still delicious as she guzzled his release. She realized squeezing her paw tightly behind her brother’s swelling made his penis spasm even greater, milking more of the tasty semen from him.

After a while Joshua gasped, “Okay, that’s getting a bit sensitive. You can let go of my penis.” He lay back, panting on the boulder while his knot shrank away.

Kera watched, intrigued as his penis diminished in size. Carefully she used her fingers to ease his sheath over the shaft that glistened with her saliva. The taste of him was strong on her tongue and she licked her muzzle, savouring the nutty flavour.

Joshua sat up, unsteady, “Wow… I mean… wow that was really good!” He kissed his sister’s maw. His semen tasted strong on her lips. “Thank you thank you.” He considered for a moment, “Although… you know I think it felt even nicer when my penis was in your girly bits.”

The twins lay back naked in the warm sun on the boulder, “Yeah. Tomorrow let’s do that instead.” Kera agreed. She ran her fingers gently over the bronze fur of her brother’s chest. “You’re the best brother ever.”

Distantly they could hear beeps and warbles drifting up from the room below. Joshua leaned over and whispered in his sister’s ear, “Don’t forget to wash your hands.”

Kera shrieked, and punched him on the shoulder.

Chapter 8: Twin tales.

Unfortunately Kera and Joshua weren’t able to return to the ruins the next day. A special college session required them to stay indoors working with a virtual tutor. College was only for one week every month but the schedule was strict so the students would get interaction with real, live others. Grumbling the twins resigned themselves to a gruelling seven days of schoolwork.

On the first night Kera snuck into her brother’s bedroom, “Hey Joshie… I wanna do the thingy with you again.”

Joshua sat up, rubbing sleep from his eyes. He was wearing powder-blue pyjamas, “Um… sure. I guess. We can’t go to the ruins at night though.”

“Silly, we can do the thingy here.” Kera was wearing matching light pink pyjamas. She sat on her brother’s bed, “But we have to be really quiet or Mum and Dad will kill us.” She began stripping off her top and pyjama pants.

“Oh, okay.” Joshua stripped naked and the youths slipped under the covers together.

They lay on their sides, facing each other. Kera raised her leg to give Joshua better access as he aligned his penis to her vulva. His penis bone easily speared through her vulva lips as he pushed full depth into her. The twins wrapped their arms around their sibling and pulled each other close. Their muzzles locked in a passionate kiss, while Joshua’s knot locked them in a far more intimate embrace.

Every night for the week the twins coupled. Their ecstasy was muffled groans and stifled cries as Joshua filled his sister again and again with his semen. They’d fall to sleep with his knot locked into her vagina. Then just before dawn the siblings would sneak to their respective rooms without their parents discovering.

They spent their day grumbling through mandatory schoolwork.

After the course ended the twins were free to resume their unfettered explorations of the world. It became common for them to wear matching tee-shirts and pants. Their mother had finally succeeded in putting their designer shorts through the laundry at least once.

Back at the Southern Ruins the twins quickly shed their clothing in the sunlight. Kera’s breasts had developed over the week. The top pair of breasts were large enough that it took Joshua’s whole hand to cup each of them. The next pair were a little smaller but still sagged forward slightly. Smaller mounds defined the last two pairs of her breasts. Joshua eagerly suckled each nipple, ministering diligently to each soft breast. He licked his tongue over her vulva to savour the taste of her. But the twins wanted to couple in the sun, on the rocks above the subterranean room. Their love-making was at once sensitive and passionate. In the private seclusion of the distant ruins for the first time in a week they could squeal out their bliss as Joshua’s semen poured into his sister.

In the warm sunshine as the afterglow of bliss drained from them the twins cuddled.

Eventually they roused. Naked, dripping whitish fluids from both their groins, the twins descended to the glittering room. A simple display pictured fingers touching two circles on the screen. The machine whistled and burbled.

“Translating: ‘Please place your’ unknown ‘in the circles on the screen’” said Joshua’s wristwatch.

“It’s a finger, you numbat!” he admonished the digital voice.

Together the twins each placed a finger in the circles on the display. Then the both yipped and suddenly drew back. They looked at each other as a tiny bead of blood welled from their fingertips, “It bit me!” they complained in unison.

The machine chirped and warbled. The tones continued for a while, then a grinning face icon flashed on the display. Abruptly the display turned off, the screen rolled into a tube and the telescoping stand retracted. The alien artefact had reverted to a small thermos-like device nestled in the dust on the floor. The twinkling lights of the room winked out, leaving featureless grey walls.

“Translating: ‘Congratulations, breeder couple. Your infertility treatment has completed successfully. Partner B is now pregnant with twins! Partner A is the verified sire!’ Translation complete.” The digital voice intoned.

Joshua looked at Kera, confused, “What did all that mean?”

An anxious expression wrinkled her face, “I think it means we’re going to have babies.”

“Wow! Neat!” Joshua’s face suddenly darkened, “Oh shit! Mum and Dad are going to kill us like a hundred times!”