Summer Heat - Chapter 41: New Experiments

The November went by and December was just around the corner. Paula was working hard on a new recipe and in the last week she finished another prototype. She was sure that it would work this time, but when she approached Zen, she still warned him that the girl who would take it might still get pregnant. Also, she had to take it every day during her heat in order for the liquid to work. Zen knew the dangers of getting one of the girls pregnant at this time, especially one that was scheduled to go home after the school. On the other hand, he trusted Paula, even though some of her experiments had backfired in the past.

Zen did not have to wait long for someone who could test it. Just at the end of November, he could smell that Tanja, the now 14 years old horse mare, was at the start of her heat. Zen approached her and asked her if she would be willing to test the liquid, even with the danger of getting pregnant again. It seemed that Tanja was concerned about getting pregnant, because she counted the months the same way Zen did. With the situation of her parents it was very unlikely that they would allow her to stay at the school after this school year and therefore, as much as she loved her foal and Zen, she was afraid what their parents would say. They were very strict and her father was a very strong built stallion that worked in the security sector. After a long discussion, and her growing need as the heat fully kicked in, she agreed to risk the prototype. Like Paula explained, she downed the vial before she went to Zhen's room, where they agreed to meet for the start of the mating. Paula reminded her, that she had to take the medicine every day, or else the effect would not work.

When Tanja entered his room, Zen directly rose from his bed and closed in to her, carefully guiding her to the bed. Her smell was so potent and strong, that his member was rock hard within seconds. It had been a while for the girl and her pussy was twitching and blinking in anticipation and arousal. The liquid had lit the fire inside her and her juices were dripping out of her strongly. Zen started with licking her and caressing her utters which drew moans and huffs from the girl. He could not keep up with this slow approach for long. After half an hour, where the girl still did not climax yet but just moaned very strong and winked with her pussy all the time, he finally decided that he would just start to mate her. Usually he wanted to make them come once before but somehow Tanja did not reach this point yet. When he, slowly at first, slipped into her hot and trenched folds, he could feel her sensitive flesh quiver around him. He picked up the pace with each push and moaned as loud as the mare. The only other sound was the wet smacking sound of his not and balls, that collided with her wet legs and pussy. Tanja spread her legs wide to give him more access and his knot slipped in and out of the horse pussy, which had always been big enough and built so differently that his knot was not contained in it. The moans of Tanja increased and grew nearly to shouts. Zen could feel that she was very sensitive and her heat felt like the flesh was burning and it gripped at his rod and knot. The familiar contraction of the orgasm however was left out and at some point, Zen could not hold his own climax back anymore and shot his semen deep into the girl. Zen howled and directly, after he was finished with his last spurt, he started to pound the moaning girl again. At the start, Zen admired the stamina of the girl, because he thought that Tanja tried to hold back her own orgasm as much as possible, but after he came a third time, and he really tried to hold back each time, and her belly started to swell under his paw, he suspected that the girl might somehow really not be able to orgasm. Even though she did not orgasm, her face was stuck in a love daze of pure bliss and horniness. Zen was so captured by his own horny desires, that had been pushed into overdrive by the potent smell and the hot and wet sleeve around his member. He did not pull out once yet and his fourth orgasm drew closer as well. The heat around his member, the quivers of her flesh every time he slid along, which told him how sensitive she was at the moment, the huffing and moaning of the girl, all this fueled his hunger to mate her more and more and had him continue. Zen achieved a seventh orgasm at the moment when the girl finally fainted. He did not pull out once during all this time and her scent even increased, but the girl could only moan. Her love tunnel was sore and even more sensitive but the anticipated climax, that her whole body and mind begged for, had not come. In the end, she dropped out from the exhaustion in body and mind and she did not feel Zen pumping into her an eighth time before he kept her bottled up and pulled the cover over both of them. The liquid inside her could not be held back by the knot, that never had been able to tie them together and with her being older and bigger now, the fit was even less tight. Zen was exhausted himself and with the bliss of her hot tunnel around him, he did not think about the fact that she did not orgasm at all and why this might be. He soon fell asleep as well, while he caressed her utters with his paws and felt the last twitches of his member inside her.

When both woke up the next morning, Zen was clearheaded enough to give the liquid to Tanja, before the started to make out again. Zen spend over an hour, trying to make the girl orgasm with his fingers and tongue. He knew all her good spots and made her moan in ecstasy until her gaze was blurry and Zen could see that she was completely in a love daze. Her fluid was gushing out of her so strong, that Zen relocated to his shower because his sheets were totally drenched. He made sure that she was drinking in between, because he was afraid that she would dry out else. After one hour without any success he finally was not able to hold back and he came on the spot when his member glided through the super moist, hot and soft folds into her canal and at the end of the push directly into her womb. Her whole body twitched and shivered from the strong arousal and exhaustion but no clamping or other signs that she reached her climax. His knot effortlessly parted her lips and popped into her snatch. The girl whinnied demanding, high in need and longing for the releasing orgasm. Her walls caressed the meaty member of Zen from all sides, making him howl and huff into her ear while he took her in various positions, finally coming back to his favorite position with her on all fours and him pumping into her in the natural mating position. Her body had become very week and relaxed and her moans were now groans, not from pain but from the unfulfilled desire to climax. Zen did everything he could to stimulate her, but stimulation seemed to not be the problem. Even more, each stimulation on her oversensitive clit, utters, the tips of her ears, the edge of her hooves and the gap between her fingers, was driving her crazy and made it even more unbearable for the girl. She longed for the stimulation in hope it would bring her to orgasm but at the same time it was like a torture for her, because the all freeing climax was yet to come. Tanja dropped out a few times and Zen was so captured in his rut from her moisture and heat, that he continued to pound her and only when Paula came back, just after Tanja woke up again exhausted and shivering after he filled her to the brim again, he stopped on her request.

"I think that the liquid somehow prevents her orgasm." Paula explained after hearing the symptoms. "This is a side effect that is most likely unbearable for Tanja. How long have you been at it?" Zen was a bit ashamed to tell Paula that, except for the night when he slept as well, he pounded her nonstop without her reaching the climax once despite all his tries. "I think you should give her some rest for the rest of the day. I know that it will also unbearable for her to fight her urges and endure the heat, but I think every stimulation will be even worse for her body right now. When I look at her squirming and groaning there, I would say another day and her mind might break or take damage." Paula instructed Zen to give her a cold shower and cool her down a bit with this. Also, the girl should drink a lot. She hoped that the side effects of the medicine would be weaker in the evening. Zen was still showering Tanja, when Sissy and Sierah came into his room. Zen knew, that Paula had sent them, because she was not sure how far she could trust Zen with not mating the girl. Even though he could be angry for this distrust, he was rather thankful. While Sierah continued to help Tanja to cool down and keep her watered, he took Sissy as a substitute and made the girl squirm under him. The younger mare did not have her first heat yet, but she learned the pleasure of his dick already. After a few groans, she started to moan soon and achieved, what her sister could not achieve, multiple orgasms until both of them rested, with Zen's knot locked deep inside her snatch. Even though her pussy had grown quite a bit, it still was tight enough to hold Zen's knot locked inside, at least when she clenched the lips together. Zen felt her clit pulse against his knot and the heat of her flesh against his own. With a bit of guild dwelling up inside, he watched Sierah, who had cleaned his bed and had Tanja sleep on a dry sheet with the warm cover over her. She guarded the older mare and with the finger in her own snatch often shot a glance over to Zen and Sissy as if she wanted to switch with the sister of her patient.

When Tanja was clear in her head again this evening, they had a long talk with Paula and together they decided, that she would bear the heat until the next morning, when the effect of the medicine would decline. She did not want to take another dose, because the two days had been too much of a torture for her already and Zen agreed. He did not want the girl to suffer and he felt guilty for being part of her suffers. Zen made all the agony up for Tanja in the next two days until her heat declined. He made her orgasm non-stop at the next day, keeping the orgasm alive with his fingers. After two hours of pleasing her, he held out much longer this day, he could not resist her presenting hind. He jumped her and soon after spurt after spurt filled her fast bulging belly. This one contribution was not the only one and Tanja demanded him again after each of his spurts, when her energy recovered a bit. For a day and a half, until her heat and arousal slowly declined, the spend most of the time connected. They moved to the big shower, because their mating was very messy and the other girls helped them to clean generously. Zen knew that the girl was pregnant and even if he had luck so far with all the pregnancies, he knew that this will cause a big problem, but at this evening, when he came the last time in the slightly bulged belly of Tanja and caressed her utters and the fur at her belly, he could not have cared less about the future. Somehow, he was used to all the problems solve themselves, that he might not even have been aware of risk and possible failure anymore. Sissy did not move away from them the whole time, demanding a bit of the attention in between their mating sessions and in very rare cases she had success. The day after, Paula invited Tanja to her laboratory to talk about the side effects and how Tanja experienced the first days of the heat while being under the influence of the medicine. From probes Paula took after the first day, she confirmed that Tanja had not become pregnant during the time she was influenced by the liquid. The side effects were absolutely no good trade for that, Tanja described them as being worse than just bearing her heat without any mating, but Paula hoped to at least get some small success or information out of the experiment. Mara insisted that Zen would take over the classes, that he skipped in the last days because he was occupied with Tanja, and she seemed to be more concerned about the pregnancy of Tanja as well than Zen. She had a lot of talks with the horse sisters, Paula, Lena and Bertha, but as far as Zen was informed, they did not find any solution to the problem yet.