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Izuku’s mother had decided that he was old enough to be left home alone as long as Izuku followed the rules she had decided on. He was having trouble following the rule of not going into the ocean while his mother was not home. Little Izuku was just so hot. Sweating in front of a fan, even though he was only wearing his little boxers. It was after lunchtime that the heat convinced him to break just the one rule.
So little Izuku put on his cute red swimming trunks and a towel before sneaking out of the house and down the short trail.
Once he made it to the beach, he took off. He sighed happily once the water was deep enough to cover most of his body. Izukus home was right next to a beautiful cove, and he had seen no one else out here.
There was a large rock near the middle of the cove that he could climb up and rest on while his feet still hung in the cool water. He laid back on the rock to enjoy the water after being so hot. Izuku fell into a relaxed state, almost meditative. Listening to the sounds of the ocean and feeling the waves lap at his legs. Izuku wasn’t sure how much time passed, but he heard a big splash near the rock he was lying on.
The boy sat up to look around but couldn’t seem to find what had made the splash. Then, with a quick tug to his leg, he was in the water. Izuku screamed out, treading water. There was something big circling him in the water. It was like nothing he had ever seen before: it was moving incredibly fast, but it seemed to be some kind of giant sea snake. The speed it moved at made the creature a blur to poor little Izuku.
Before Izuku could even think about trying to get away, the creature wrapped itself around him. Izuku squeaked at the pressure as the creature’s body twisted and squeezed his much, much smaller one.
Izuku couldn’t help it, as tears poured down his cheeks. Small whimpers escaped with his tears. He was sure that whatever had captured him would eat him.
There was a face in front of him, human except for the gills on the cheeks and small fins poking out from the creature’s hair. Izuku gasped at how pretty it was up close, but knew even pretty animals hunt for their food. He whimpered again, struggling against the snake part of the creature’s body.
The creature loosened his grip on the tiny boy’s body, but only enough to stop the painful pressure. He cooed at Izuku, then licked up the salty tears on the tiny human cheeks.
Izuku froze, whimpering even louder, and had struggled again. He didn’t want to be eaten even by some beautiful, mystical creature. “P-please don’t e-eat m-me.” Izuku wailed as he cried hysterically.
Izuku couldn’t see the creature roll his eyes with a smirk. He did, however, feel his body being moved to the rock, the creature still securely wrapped around him. But when he opened his eyes again, both he and the creature were sitting on the rock.
“Don’t worry, guppy, I will not eat you... at least in any way that would hurt you.” The creature’s voice was deep but soothing.
“You p-promise?” Izuku asked with a sniffle, his tiny hands gently laying on top of the pretty dark green scales.
The creature laughed and nodded at the tiny boy. “Yes, I promise guppy. My name’s Katsuki. What’s your name, pretty?” Izuku nervously shifted, trying to wiggle his hips out of the snake-like body. Katsuki tsked and squeezed the boy tight just enough to cause the slightest pain.
“Stay still and answer me, guppy.” Katsuki didn’t seem angry, but it was obvious even too little Izuku that it was a command he expected Izuku to obey. Izuku gulped and stopped his attempts. “My name is Izuku,” the little boy said, while trying to wipe away his tears. Katsuki’s body slithered around Izuku’s the tiny boy’s body engulfed by the other, hidden away from sight.
“Well, little guppy Izuku, what are you doing out in the middle of a cove all alone?” Katsuki had maneuvered his body so that he could rest his arms on his tail and look down at Izuku. Izuku could see the creature better now that he didn’t have tears in his eyes. Katuski’s forked, pointy tongue moved across his lips like lighting, and Izuku jumped before remembering he needed to answer.
“It was too hot today but my mother had to go to work so I came by myself.” Izuku explained, sneaking glances up at Katuski before his eyes would dart away, when he realized Katuski continued to stare at him unrelentingly.
Katsuki moved even closer to Izuku’s face, the tongue flashing out like lighting again, licking at Izuku’s lips. “What a brave little guppy I found.” Katsuki said. “Do you want to know why I’m in the cove today, lovely guppy?” He asked Izuku as his tongue moved quickly once again, this time wrapping around Izukus throat, but not enough to cut off his air supply. Izuku shivered and tried his best not to move anymore.
“Y-yes, why are you here?” Izuku asked, looking up at the godlike creature above him. Katsuki smiled widely, showing sharp shark-like teeth. He retracts his tongue from around Izukus throat and back into his mouth.
“Well, little guppy, I was coming to find a place to keep my egg warm, and I think I have found the perfect place.” Katsuki said as he reached out and slid one of Izuku’s curls out of his face. The massive tail that had been squeezing and sliding against Izukus body became loose and then Katsuki was picking him up and rearranging them. Now Izuku was sitting on the creature’s lap. It wrapped the long dark green tail around so that just the tip laid over Izuku’s small soft thigh.
Izuku wasn’t sure what was happening, but the creature, Katsuki, wasn’t hurting him or trying to eat him, so he didn’t struggle. Katsuki slipped his massive human like arms underneath Izuku’s so that the small boy wouldn’t slide away. “Dont worry little guppy, I’ll make it feel so good for you.” He whispered into Izukus’ ear. A finger slides down Izukus side and he shivers on top of Katsukis tail, almost sliding down if not for Katsukis tight grip on his chest.
Katsuki moved Izukus’ small body over to the side a little, petting his hair and licking his ear with his pointed tongue. Katss free hand moves to a spot bellow where skin meets scales, huffs hot air into Izuku’s ear that makes him shiver. Izuku feels warm and embarrassed. Katsukis’ hand moves to Izuku’s mouth. “Suck for me, little guppy.” He says putting two tips of his long thick fingers on Izukus’ bottom lip. “Please little one, I need help to get my egg to come out.” Katsuki pokes the bottom of his lip again and Izuku gives in, letting the fingers push into his mouth. "Good guppy” Katsuki moans next to his throat.
It seemed to Izuku that the creature was in pain. His skin was getting redder and his moans were getting louder. Izuku didn’t want Katsuki to be in pain, so he licked between the fingers in his mouth and sucked on them. The boy couldn’t fit the fingers all the way in his mouth so the parts he couldn’t reach he licked, his tongue moving up and down on the creature’s fingers.
“Is that okay, Katsuki?” Izuku asked after a few minutes. Katsuki groaned loudly and nodded before moving to the spot he had been touching earlier. Izuku watched amazed as the creature ran his two wet fingers down a tiny vertical slit Izuku hadn’t seen on the scales before. The fingers were dipping in side, sliding in and out. Katsuki was panting in his ear. He seemed to search for something inside the slit. Katsuki jerked forward, whining as his two fingers wrapped around a fat pink tentacle like thing and gently guided it out of the creature’s slit.
“Please, little guppy, Izuku, can you touch it for me? The slick on it will make you feel better too. I promise I won’t hurt you” Katsuki seemed very different now, needy and soft. Izuku didn’t even know much about human parts, so he wasn’t sure what Katsuki needed, but he wanted to help. So the small boy reached his hand out and pet the pink tentacle with his small fingers. Katsuki jerked up again with a loud whine and Izuku saw more of the clear sticky slick push out of the slit. Izuku scooted down the giant body until he reached the tentacle.
Izuku bit his soft plump lip and looked over his shoulder to Katsuki. The creature whimpered at him, and the tentacle rubbed against Izuku’s wrist. Izuku looked back to the tentacle in front of him. He reached out his tiny fingers and gathered some of the clear slick and rubbed it between his fingers. It was so warm; it smelt so sweet and made his skin tingle. Izuku gathered as much of it as possible onto his fingers and then gently grabbed the tentacle. Izuku squeezed it and the smaller tip wrapped around his wrist, spreading the slick onto Izuku as well.
Katsuki was squirming beneath the small boy but held onto his plump hips so he wouldn’t fall off of Katsuki. Heat was overtaking the merman. He could feel himself grow close as the innocent boy played with his fat tentacle. Izuku had taken to rubbing both his hands down the sides of the tentacle and squeezing in different spots. “Guppy, please more, please guppy.” Katsuki said after groaning loudly again. Izuku wasn’t sure what else he could do. The only thing he that came to mind was to use his mouth as well. He bent down so his lips were closer to the tip of the tentacle, and then he gently sucked at the tip. Katuski’s reaction was immediate. His fingers dug in to Izukus hips and his back arched high. Izuku kept moving his hands down, squeezing at the base of the tentacle, and his mouth sucked on the tip, his tongue playing with it as well. Izuku could feel the tip open up and curiously stuck his tongue softly down the opening.
That sent Katsuki over the edge instantly. Thick globs of the slick pushing into little Izukus mouth, Katuski rutting into the air as he rode out his orgasm. It shocked Izuku when the sweet slick started coming out of the tip, but it tasted so good and made his tummy warm on the inside. He tried to drink all of it down as Katuski thrashed around under him. He was running out of air though, and had to pull away. The giant snake calmed and pulled Izuku up closer to his face, nuzzling the small boy with his face, licking up the slick that had dripped down the little one’s chin and neck.
Izuku had felt warm and tingly before drinking a lot of the slick, but now he found it hard to think. He felt so good though that he couldn’t worry, and he only giggled at the massive creature’s doubting. Soon, though, Izuku was getting too hot. Katsuki was petting him on his sides through his hair, making small chirping noises that seemed to be some kind of praise Izuku couldn’t understand. Izuku squirmed and whined. His private parts were hurting and the way his dry swim trunks rubbed against it made it worse. Izuku continued whining till the creature seemed to take notice. Katsuki picked him up, trying to figure out what was wrong with the little guppy.
Katsuki saw it then the poor guppy was all flushed and panting. The cloth that he was wearing was sticking out slightly right above his legs. Katuski laughed the poor thing drank too much of his slick. He brought Izuku back closer to his chest and rubbed the soft skin of the boy’s stomach. “Shh guppy, it is okay, I’ll help you too before we get to the egg.” He whispered. Izuku continued whining, grabbing at Katsuki’s arms and chest. Katsuki shushed him again before gently and carefully ripping the material Izuku was wearing. Katsuki chirped when he saw the small penis standing hard. It was so small, especially compared to Katsukis tentacle, a tiny little thing, but it was red and twitching as Izuku whimpered. Katsuki set the boy lower near his tentacle.
Izuku let out a small sob as the tentacle bumped against his tiny little cock. Katsuki bent down to kiss the boy while he let his tentacle play with the small little guppy. Relief washed over Izukus body as the tentacle explored his small body. It seemed to like his penis and wrapped around it, squeezing and moving against it quickly. “K-katsuki, it h-hurts” Izuku whimpered once again.
Katsuki smiled, licking up the boy’s tears with his forked tongue before moaning at the salty taste. “Shh shh little guppy, it’ll be better soon just let me help” He said, his tongue gliding down Izukus chest easily and flicking over the soft light pink nipples.
The small boy was shivering so hard from pleasure, Katsuki thought his teeth would rattle. Everything Katsuki did to him sent electric currents through his body and straight to the end of his tiny cock. The tentacle grew even more excited when clear pre-cum leaked from Izuku. Izukus’ cock had never done that before, but Katsuki seemed to think it was okay, so he wouldn’t worry about it.
Izuku moaned at the combination of Katsukis tentacle wrapping around and sliding along his cock, and the creature’s tongue relentlessly playing with his small nipples. Izukus tiny body tightened up and then thick white cum shot out of his tiny cock and onto the fat tentacle wrapped around it.
Izuku whimpered from the sensitivity of his penis and the tentacle that would not detach from it. Katsuki’s hand appeared and started to gently pry his fat tentacle off of the baby guppy’s tiny cock. He moaned, their fluids mix underneath his hand. “Okay, guppy time for the egg, it might feel strange, but I promise I’ll take care of you.” He murmured as he turned the boy around to face him. Katsuki used his tongue to give the little one a quick cleaning.
Soon Katsuki had cleaned everywhere with his tongue except the boy’s hole. He had been patient so that the guppy wouldn’t be harmed by the egg. Katsuki couldn’t wait anymore. He moved the boy closer to his face and slithered his tongue underneath the boy’s legs, then he pulled Izukus thighs apart so he would have easier access. His tongue swept over the boy’s small hole. Izuku spasmed and tried to pull his thighs shut, a loud whimper torn from his throat. Katsuki kept his hands on the little one’s thighs so they could not close. When he looked up at Izukus face, he realized the boy isn’t very coherent, little babbles and whimpers coming from his lips.
Katsuki smirked slightly, his tongue still probing at the little guppies entrance. Slowly the hole opened to his tongue, and he fucked the hole. Izuku cried out loudly when Katsuki’s tongue would brush against a small spot. Katsuki tucked that away for later, hoping he could get his fat tentacle to cooperate and push into the same spot. He had been taking his time with the boy’s hole, stretching it as much as possible with his tongue. Pushing the long length up into the boy’s insides, twisting and prodding. Izuku sobbed above him babbling nonsense, Katsukis name was the only thing he could pick out of the words.
The giant creature laid the small boy on the rocks and then moved over him so that his tentacle would reach his tiny little hole. He wrapped his tail around one of the boy’s small legs and lifted it out of the way. The fat tentacle had a mind of its own and reached out the tip slipping inside easily. Katsuki was getting close again, could feel the buildup of slick. He tried to hold back to get his tentacle under control, put it pushed fast inside stretching Izukus rim. There was something about the earlier spot that Izuku seemed to like that his tentacle did, too. It pushed and massaged at the spot roughly, making Izuku under neath him scream out and clutch at Katsukis arms. Izuku was tightening around him more and more. His fat tentacle kept pushing inside and against that spot.
As soon as Katsukis tentacle had made it all the way inside Izuku, Katsuki fell over the edge again. Large amounts of slick poured into the small, guppies insides. While the slick pumping out of his tentacle with hard constant pressure on Izukus prostate had Izuku coming onto his and Katsukis chests. Izuku was a sobbing mess, fat tears and even some snot was covering his face, and even though the poor little boy had just came his tiny baby cock was still hard, red and throbbing between the boy’s plump soft thighs.
Katsuki tried his best to soothe the boy, but it was best if he wasn’t coherent during the next part. Katsuki’s fat pink tentacle had spread apart, making room for the egg to pass through. The egg itself wouldn’t be that big, quite small, at least to Katsuki. Katsuki sighed softly as the egg pushed through his tentacle. It was at the baby guppies rim now, Izuku was still sniffling beneath him. Katsuki didn’t want the poor guppy traumatized, so he wrapped two fingers around the tiny cock and played with it. Izuku moaned and relaxed enough that the tip of the egg had pushed past his rim. Katsuki grunted under him, straining a little to push the egg the rest of the way in. Centimeter by centimeter it made its way in, Katsuki had distracted the little one enough that he was now moaning. Izuku didn’t really understand anything that was happening. The pleasure was overwhelming, and the boy came again from the pressure on his rim. Katsuki smiled and chirped happily again, so proud of his little guppy.
Katsuki was close again too. Katsuki thrusted into the small boy’s hole, trying to push the egg into place. He rearranged the boy so that he had a little more room. Katsukis tongue could also reach the tiny cock in this position. His tongue wrapped around it, squeezing and licking.
Katsuki pushed softly against the guppies stomach and then the egg slipped from the tip of his tentacle and lodge into the small boy’s stomach. Izuku screamed then, loud and wet. Cum shot from his tiny cock into his own face and then Izukus mind faded to darkness.
Katsuki smiled. His egg was safe and sound inside the guppy. The guppy that he would keep watch over until the egg was ready. Katsuki yawned as he picked up the baby guppy and curled his body around him before drifting off to sleep himself.