Work Text:
“Thank you for participating in our program of saving endangered species from extinction.” The young lady smiled at Katsuki as she led him to the breeding chamber.
Katsuki was nervous, but on the other hand excited like never before. He heard about this program from Denki who was a frequent volunteer here, and couldn’t get it out of his head since. The thought of getting fucked withing every inch on his body and being helpful in the proces. In space there were lots of species that were near extension, where many of them were caused by humans, and now it was their turn to fix it. Before he got there he got information about the species that he would get bred by today.
There were only tens of ‘Kiritans’ on their home planet. It was colonised by humans a few hundreds years ago. These people were hunting another species of mammals that lived there, that they later learned was important for Kiritan’s reproduction. They are all males and used these mammals as incubators for their offsprings. Without them they couldn’t reproduce as much as they needed and their numbers dropped rapidly.
They surely needed help and who else should have done it than who caused it. And this was Katsuki’s role. He will get his womb pumped full of eggs and then bear them for the next six months till they would be ready to hatch. During that time it would be up to him if he stayed here or would go home. After a few minutes of walking through the facility they got to the right chamber.
“You don’t have to be afraid. Eijirou might look scary, but he won’t hurt you. He is known to be really gentle to our volunteers.” Once Katsuki felt ready, the lady put a gag on him with a few small holes for better breathing. The plug was already snuggled in his ass. It was mandatory for breeding with this species. If he was not plugged there was a possibility that he would get bred in the wrong hole. Then he was let inside, the door locked behind him.
The chamber was dark. Kiritans were night beings, during the day they stayed in their dens in deep caves. That was why people discovered them when it was almost late. Katsuki looked around, his eyes adjusting to the dark. He heard movements in front of him, but couldn’t see much. Suddenly he felt a wet touch on his arm. He shivered but stepped forwards. As he got near, more tentacles wrapped around his exposed body. The feeling was weird, he never experienced anything similar. Katsuki let himself be dragged further into the chamber, more and more tentacles around him.
He shrieked when he was lifted to the air, not able to do anything. He was quickly covered in sweet smelling slick, it felt sticky on his skin and made a mess from his hair. He slowly started to feel hot. Breathing got faster and his skin more sensitive. Then he remembered another fact about Eijirou’s species. The slick that he excreted worked as a strong aphrodisiac for mammals. It made them more willing to be used. Horny incubators didn’t fight back.
Katsuki felt his own slick run down his thighs. No one was able to get him this wet, and now it took so little. His pussy throbbed as it begged to be filled. He felt almost painfully empty. He thought that Eijirou would want to lay his eggs as soon as possible, but it seemed that this bastard wanted to play with him first. Two tentacles with holes at their ends found his nipples and stuck to them, slowly sucking. Third went right after Katsuki’s clit. It was clear that Eijirou knew more than well how to please a human.
Katsuki whined as he was stimulated. His poor clit twitched every time it was sucked a little bit too hard. He was quickly getting to climax before he understood how mean Eijirou could be. He was almost there. Pussy gushing like an open tap, pulsing with the need. He was whining through the gag, if he didn’t have it, he would beg for it. He was shaking, and couldn't hold back the tears forming in his eyes. Just a little more. But then it stopped.
All of the tentacles that weren't holding him went away from him. He was left panting, crying and on the edge. He thrusted his hips, trying to find any friction that would help him get off, but was met with nothing but cold air. Eijirou left him hanging there for several minutes. Katsuki still felt like his insides were burning but the familiar pressure in his abdomen went away. He was calming down, even if a little tensed as he didn’t exactly know what was going on, when he yelped in combination of pain and pleasure.
That fucker really just spanked him with one of his tentacles across his pussy, without doupt aiming at the oversensitive clit. Katsuki wanted to yell at him through the gag, but before he could he felt another stinging slap. He was spanked again and again, his pussy surely getting a lovely shade of red from the abuse, and his protests slowly changed into muffled moans.
He couldn't deny that even with the pain it felt so good. Maybe it was because of the afrodisiacs, or it was just something he didn’t know about himself, but in the end it didn't matter. All he could think of was the pleasure that went from his crotch to his entire body. His muscles tensed and toes curled with every spank.
Once again he felt that he was about to cum. Just when he was almost there, an impossibly wide tentacle sinked right inside his pussy, throwing him suddenly over the edge. Katsuki was screaming as his whole body convulsed. It was the most intense orgasm he ever had. Slick squirting out around the tentacle making the puddle under him even bigger. Katsuki could swear that he black out for a few minutes from how hard he came.
At the moment he would do anything for at least half an hour to rest, but Eijirou was having none of it. He took the tentacle almost fully out and then thursted it back inside. A few slower hard thrusts as if he was finding out what Katsuki could take, but then he picked up the speed. He was sure that he wouldn’t have to worry about hurting his mate, so nothing was stopping him from wild fucking that made Katsuki bounce up and down.
Katsuki was sobbing, stimulated too soon after cumming. The sensations were too much, moreover when the three tentacles returned to their places. Katsuki shook from oversensitivity. Too much pleasure to endure. And he couldn’t do anything about it. He was helpless and in mercy of his slimy lover. But it didn’t look like Eijirou would have much mercy for him.
Katsuki didn’t know how many times he came after that, it was one big mush of pleasure. His chin was covered in drool and eyes rolled back, too fuck out to do anything but hickup with every thrust. It felt like an infinity went by when Ejirou finally stopped. But then the tentacle started swelling. Katsuki whined silently as his pussy was forced to accommodate the girth. He didn’t think that he could take more, when it happened.
Thick liquid started to fill up his hungry belly. Another thing that proved how well adapted the species was. This fluid managed to stimulate Katsuki’s cervix to spread, so the tentacle could go right inside his womb. Then he would pour more and more of it into his womb till it would be full and ready to take all the eggs. Katsuki whimpered as he watched his stomach getting bigger. He wasn’t sure how much Eijirou wanted to get inside him, but it felt like it would be a few litres. Katsuki felt so tired, he wanted to sleep so much, but with his pussy plugged like this he couldn’t. He had to wait till it was over.
He felt relief when the stream stopped, but then he remembered that now came the main part. He couldn’t see it in the dark, but he clearly felt it when the first egg got to the entrance of his pussy. It could be big maybe as a lemon, size still manageable to comfortably pass through his gaping hole. It went slowly, dragging across his g-spot. Massaging it, making Katsuki whine and cry out loud. One tentacle carefully caressed his hips, probably trying to help him relax. Katsuki could swear that he even heard a weird sound coming from behind him. Like if his mate was cooing at him.
It could take several minutes for Eijirou to push it all the way. And with how short the way was, it stimulated Katsuki so much. He could feel as it finally popped out of the tentacle and settled deep in his womb. One egg inside him, another already waiting against his pussy, and who knew how many of them were waiting for their turn.
Katsuki groaned, blinking a few times, the light making it hard to keep his eyes open. “Please stay still, I’m almost finished with my tests.” The lady put some device on his bloated belly. “It’s amazing. Eijirou maximally laid five eggs in the past, but you carry nine perfectly healthy eggs inside of you!” She shined with excitement. Katsuki wasn’t sure at which moment he passed out. His body was too tired to stay awake for the whole process of laying. But even if he felt like a shit, he was also proud. He took so many more than others could.
Also for the first time he could get a better look at Eijirou’s tentacles that were still holding him. They had bright red colour with thin black stripes. They were pretty in their own way. “Now there is the question if you would like to stay here while you’re with eggs or you would rather go home.” The lady got his attention again. Originally he wanted to spend that time at home, but now when he felt the warmth surrounding him, he didn’t want to leave. So he stayed.
The facility let his family and friends know so they wouldn’t be worried. His job was also notified. They didn’t have a problem with him being away for a half of the year as companies were compensated when their employee was volunteering. They told Katsuki that he would stay in the chamber and at stated time they would be going there to get him food and clean him. Also the light from the hall outside of the chamber should be enough for his eyes to not get too used to dark.
Katsuki wasn’t sure what he would do during all that time between visits, since Eijirou didn’t really let him out of his embrace. But then he felt the tentacle teasing his sore and worn out pussy. He should have known that Eijirou wouldn’t stop with fucking him once he was succesfuly bred. At least his pussy was still wet and stretched enough to welcome the tentacle without problem.
It started slowly. Almost undetectable movement inside his stomach that kept growing for the past months. His stomach got so big, he looked as if he was pregnant at least with twins or triplets. He was surprised that he didn’t have any stretch marks, but then the lady explained that Eijirou’s slick, among other things, was really good for human skin. With this Katuski would think that people would gather it and sell it, with how many uses it could have.
It took him a while before Katsuki realised what was going on. The eggs were ready, hatching inside him, and wanting to get out. Eijirou sensed it too and lowered Katsuki on the floor, so they wouldn’t fall from too high. First came out the liquid, splashing around him. It eased the pressure that he felt inside him.
Then he felt wiggling in his pussy as the first one got through his cervix. Katsuki felt almost bad from how arousing it was. He was giving birth and getting off to it. They stretched his pussy just as good as Eijirou with his tentacles, but it was even better since they had their own little tentacles that caressed Katsuki’s sensitive walls.
But it didn’t seem that Eijirou minded it as his tentacle playfully flicked Katsuki’s clit before sucking it in. It didn’t take long for the first one to get out. A small bundle of tentacles tapping on his thighs. Ejirou helped it to get on Katsuki’s chest, where it was curiously teasing his nipple, as the second one was coming. Katsuki managed to come two times before all of them were out.
His heart swelled in pride as he watched the babies. His babies! They were moving on him, his warm body making them comfortable. He almost didn’t want to let them go. He knew that small Kiritans stayed with their parents only for a short time. But he still had some time to enjoy this almost domestic feeling.
The first day he got into the chamber, he thought that the lady was lying to him, when she said that Eijirou was gentle. But the longer he was there he understood that she was right after all. Eijirou might have played with him a lot.
Denying orgasms and then throwing several of them on him. But he never hurt him. Never made him feel unsafe. Katsuki grew to kinda like the alien that couldn’t even communicate the same way as humans did. How could he not when he was taken care of so well. At the end of their play time Katsuki was never left unsatisfied.
Also when it was time for Katsuki to get food, Eijirou didn’t let the lady do it herself. He took every piece of food in one of his smaller tentacles and gave it to Katsuki by himself. It made the blond feel almost loved. Not like he was only fuck toy for Eijirou and incubator for his offsprings.
It was a few months since he walked out of the facility. He felt the urge to return and just decided that it might be a good time to go again, when he got a call. It was the facility. They had a problem with Eijirou. He was the one that gave them the most offsprings from all the Kiritans they had. But now he refused to breed any volunteer they took to him. That was causing them big problems.
They searched and Katsuki was the last one that Eijirou bred. They suspected that Eijirou imprinted on him. It was happening in the wild too from time to time. When Kiritan found a good mate they kept them with themselves and bred them repeatedly. They were almost sure that it was this case, since Eijirou was completely healthy and able to produce eggs.
They couldn’t force Katsuki, but they straight up begged him to come and consider a longer stay. Kiritans had a limited amount of eggs that they were able to produce during their life and Eijirou wasn’t even in half. And all of them would be wasted without Katsuki.
They calculated that it would take about five years before he would lay every egg he was able to. Five years at the facility, in the embrace of the red tentacles. About ten times of being bred, pumping full till he would almost burst, and ten times of giving birth. Also carring the eggs for six months each time while getting fucked multiple times every day.
Katsuki immediately told them that they could count on him.