Because It's Fun, That's Why

Pairing: Midoriya Izuku/Midoriya Izuku 

Rating: 18+

Tags: Selfcest, Rough Sex, Light bleeding, Blowjobs, Huge Penis, Alternate Universe 

Summary: For Deku, there's nothing more fun than jumping to all the different universes and stealing little, quirkless Izuku right out from under the nose of All Might. Well, no, that's not exactly true. There is one thing that's more fun and that's transmitting a small piece of his quirk to his younger, alternate self via stuffing him full of his cum. 

This is a commission for ShindoVanitas! 

-  

Ah fuck, why did the jumps always have to be so brutal? Though, he didn’t know what else he expected from hopping from dimension to dimension. It’d be even weirder if it was all sunshine and daises to just step out of one world and into another. Still, as he was lying on the cold pavement, staring up into a bright, blue sky, he was really wishing for some daises. Groaning softly, Deku pushed a hand through his thick, unruly hair. Dull, aching pain radiated out from his lower back. For a normal person, that pain would probably be a lot worse, considering that he had hit the pavement with enough force to make him bounce off of it but that was one upside of repeatedly destroying his body in numerous ways. Pain stopped meaning anything. Didn’t stop it from being annoying, though. Wasn’t even a good type of pain, either. It just thudded again, obnoxiously reminding him that he could have tried to make the landing but he was too damn lazy. Letting his hand fall away, Deku stared up into that bright blue sky for a few moments then hopped to his feet. He stretched his arms high up over his head, then did a couple of swivels, making sure to adequately stretch out the muscles in his back, sides and neck. The pain flared up a bit as he moved about but quickly faded back down once he was finished.  

Placing his hands on his hips, Deku took a closer look at his surroundings. What he saw wasn’t a surprise. He always landed in the same spot and, 95% of the time, he saw the same thing: the street over from his apartment complex. The little details were always different – couldn’t expect everything to be the same across dimension but it was all insignificant shit. A kid rolled by on a bike instead of walking or there was an ambulance siren going off in the distance or a sparrow flew by inside of a pigeon…little stuff that made sense it’d be different. Thousands of little decisions were made every day in this new world – decisions that were completely different from the ones made in another. It’s what set everything apart. Course, he’d visited some worlds where the little changes hardly even pinged on his radar, either because there simply weren’t any to be found and the world was disconcertingly close to another or the big changes were too massive, completely swallowing up any little things that might’ve been there. Thankfully, he hadn’t stumbled across to many of the latter. He preferred it this way – made it so much easier to do what he wanted to. 

Speaking of which, it was almost time. He didn’t have to glance at his phone to know that. Do something long enough and it becomes an instinct. Setting off down the street, he didn’t bother glancing at the street signs or any potential landmarks – he knew exactly where he was going. Ducking into a small street that was barely big enough for his broad shoulders to fit through, Deku popped out on the other side just in time to step in front of a very special kid. As usual, his head was down. Small hands were wrapped tightly around the straps of his backpack. Twisting around so he was fully facing him, Deku opened his arms so the little cutie would walk straight into him. Predictably, he did just as Deku planned – he didn’t know how someone could be so unaware of his surroundings that he’d walk straight into the arms of a stranger. Though, the poor kid did have a lot on his mind. Without hesitation, the boy bumped right into him. The curve of his forehead bumped against his chest. He left out the cutest ‘OOMPH!’ sound. Before he could step back, Deku wrapped his arms around him, smiling brightly when the kid looked up at him.

“Hey there…Izuku.”

Mouth hanging open, Izuku gawked up at him, eyes stretched open wide, “Y…You’re me!”

Deku chuckled, pleased. Well, that was a bit of a surprise. His younger, alternate self rarely caught on right away that he was an older version of him. It usually took some convincing – details about their past that only they would know, shoving him his old notebook that was full of scribblings about Pros, stuff that was so close and personal to them that there was no way he couldn’t be an older version. Looked like he was in for a good time this go around – he had discovered across his multiple jumps that when his younger self immediately caught on, he was so much more interesting than the ones who needed proof. Stepping back a little so Izuku could get a better look at him but still keeping his hands on his arms, Deku’s grin widened when Izuku made no attempt to hide his gaze eagerly roaming over his significantly bigger, muscular body. 

“That’s right.” He said warmly, “I’m you, from around 27 years into the future. I know you’ve got a lot of questions so let me go ahead and answer them: yes, this is possible because of a quirk; yes, I do have a quirk; yes, I did become a Pro with my quirk; no, All Might isn’t the best Pro in existence anymore…I am, or was, before I retired.” Deku paused for affect, thoroughly enjoying the shocked look Izuku was wearing as he digested what he’d just been told then leaned down to bring his face close to Izuku’s. He subtly inhaled to pull in his sweet, alluring scent. It was so clean and pure… so different from his own. It was probably just a figment of his imagination but… he didn’t smell this good anymore. Years of being a Pro had done that to him. He only became of this drastic change in scent when he mistakenly jumped into a world that was only a year ahead of his own. The Izuku of that world was an interesting one – not any worse or better than him, just…interesting but meeting him made Deku realize that his smell had drastically changed from when he was a kid, and not for the better. He could hardly stand being around that Izuku because he smelled so bad. After that, Deku couldn’t get enough of younger Izuku’s scent. 

Brushing the tips of his fingers along the curve of Izuku’s cheek, his grin widening at the very obvious shiver that raced through his small body, he murmured softly, “Do you not believe me?”

Izuku was quiet for a moment more, seemingly too shocked by what he had just been told then, to Deku’s surprise, his face split open in a huge, delighted grin. Surging forward, his eyes sparkling with adorable energy, hands clasped in loose fists in front of him, he declared, “I became a Pro?! That’s so cool! You’re so cool! You’re so big and muscular! Your body is amazing, do you work out a lot or is it because of your quirk?!”

Surprised that his first question wasn’t about All Might (his younger selves usually always asked about him first), Deku laughed, “It’s all natural muscle that I’ve built up over the years.”

Curling his fingers around Izuku’s thin wrists, Deku lead his small hands to his chest, pressing them flat against his prominent pecs. A brilliant flush of red poured into Izuku’s freckled cheeks. This little guy was full of surprises. It usually took them a couple moments to warm up to the idea of touching him but him…he started moving his hands right away – didn’t need any prompting from Deku, just got to roaming, eagerly exploring the lines and angles of his muscles. A lazy spark of pleasure rolled down to his cock, inciting it to stir. Fuck… he had never encountered one of his younger selves who was so… eager. This was going to be a lot easier than usual, which he wasn’t about to complain about. One of Izuku’s small hands grazed over his nipples, making him shudder. Izuku’s gaze flickered up to his face then back down to his chest. He did it again – both sides this time, pressing his hands more firmly to the plump curve of his pecs. Deku thrust his chest forward into his touch, not bothering to hold back a pleased moan. Oh, this kid was already spectacular. He couldn’t wait to see how he would be with what came next. 

“How…” Izuku said hesitantly, his cheeks burning red, peering up at him through thick lashes, “How did I get a quirk?”

The corners of Deku’s lips curled up in a lazy smile, “Do you want one, Izuku?”

Izuku nodded, “Y-Yeah. It’s All Might’s, right? He…he said he was going to give me his. He said I won’t be quirkless anymore. That’s what happened to you, right?”

The corner of Deku’s eyebrow twitched. Never seemed to matter how many times he heard that, it still managed to piss him off. Cocking his head, Deku said, “It was All Might’s but over time, I mastered it, changed it until it was no longer just a quirk that was handed to me but was mine. Truly mine – stronger, better than his ever could be. And now, I want to give it to you.”

“Huh? Me?”

Deku nodded somberly, “There’s millions of realities, and part of my quirk allows me to jump between them. When I found out that I needed to give my quirk to someone else, I decided to give it to my younger self…to you, so that you could beat fate and become the Pro that you’ve always wanted to be.”

“There’s millions of realities…and millions of me but you chose me?”

“Yup.” Deku lied through his teeth, cupping Izuku’s burning hot cheek, “It was a pretty torturous decision but…you…you deserve this so much. You could do so much good. You’ll be an incredible Pro, one who will show this world what a Hero truly is.”

“But All Might-“

“Is giving you an inferior version of the quirk.” Deku said firmly, “I’ve seen it millions of times, Izuku. He gives us the garbage scraps and expects us to break our bodies to develop the quirk. Some of us can’t even manage to get to 50%. They’ll never be as powerful as they could be but you,” Deku offered a faint hint of a smile, “you could be so much stronger than him…the strongest Pro in all existence.”

“Why…why would you give me the quirk? You aren’t hurt like All Might, are you?”

“No, I’m not in the same position as him.” Deku laid a hand over his heart, putting a carefully crafted expression of soft regret, “I just know when it’s time for it to go to someone else. I think I’ve gotten this quirk as powerful as I can. Now, it needs to be given to someone else. It needs to be given,” Deku brushed the pad of his thumb over Izuku’s cheek, “to you.”

Izuku’s eyes widened. He inhaled sharply, his lips trembling then declared enthusiastically, “You’ll really give it to me?!”

“Yeah, I will.”

“Then I’ll graciously accept.” Izuku lowered his brows in an adorable expression of determination. Fuck, he was too cute. 

“I knew you would.” Deku smiled slightly, giving his soft hair a ruffle, “Now, I just got to give it to you.”

“How do you do that?”

His smile widened. Finally, the fun part. Taking one of Izuku’s hands, he slowly led it down the length of his body until it was hovering over his crotch. Izuku let out the cutest gasp when he pressed his hand flush against his half-hard cock. It twitched underneath the pressure. The color in Izuku’s face deepened to an even darker shade of red. Blinking rapidly, a noticeable tremble racing through his small, thin body, he looked up at Deku. There was no disgust, no horror at what he was being made to do. Only a bright, blazing, wanting heat burning in those big, expressive eyes. Normally, he’d pause just long enough to explain that this was the only way to pass on the quirk – no, it couldn’t be given with any other bodily excretion, it had to be his semen – but this Izuku’s reactions… he didn’t feel the need to. Deku yanked Izuku into the small side street. There wouldn’t be anyone about this time of day. Even if there was, they wouldn’t glance down here. The space was just big enough for the both of them, though it was a tight squeeze. 

Stopping halfway down, he pushed Izuku up against the wall. Keeping one hand planted in the center of his chest, he reached down with the other to expertly tug open the folds of his pants, slipping a hand inside to pull of his now fully erect, throbbing cock. Izuku’s eyes widened. His jaw dropped a little. Deku couldn’t blame him for being shocked. One of the many side effects of his quirk was majorly beefing him up down there. He had been fairly well endowed before but the quirk had ramped that up to monstrous levels. He could rarely get this fat monster into his younger selves’ mouths and often had to forcibly introduce them to how much they loved it when it burned as he shoved it in. The number of his younger selves he had made cum just from impaling them on his thick, fat length was a bragging right in his mind. It always made him giddy to know that there were Izukus all across the multi-verse who had their kink of having their dry, tight hole pounded without any kind of lube or prep awakened by his big prick. 

He was so distracted by the triumphant feeling of fucking his younger selves senseless that he didn’t notice his current Izuku reaching out. Warm, soft fingers brushed against the underside of his cock, jerking him back to the present moment with a sharp gasp. Laughing low in his throat, Deku thrust forward, rubbing his dick against Izuku’s hand. He was flushed such an intense color of red that he was a little worried he’d might pass out. Dragging his tongue over his lower lip, Deku gave his hips an enticing wiggle. It had just the reaction he wanted. Emboldened, Izuku hesitantly wrapped his thin fingers around his length. It was almost a little comical – he couldn’t get his fingers fully around it. The tips didn’t even come close to touching. Panting raggedly, fat droplets of sweat standing out prominently on his forehead, locks of hair clinging to his flushed skin, Izuku slowly, shakily looked up at him, uncertainty clear in his expression. A quick glance down revealed something that made his dick twitch. Izuku was visibly erect. There was a large wet spot growing at the front of his crotch. Was his underwear all soggy now? Fuck, he couldn’t wait to see. A lot of his younger selves came just from sucking him. He wondered if this adorable cutie would do the same. Going off how he was already acting, it would be a shock if he didn’t. 

“Wha…what do I-?”

“Most effective way to give the quirk to you is via my seed.”

“Seed?” Izuku whispered, his gaze dropping back down to his cock. 

“Yeah, it makes it so,” he drew out the ‘o’ sound to really emphasize his point, “much easier for you to absorb it.”

“I…I’ve never done anything like this before. I don’t know what to do.”

“That’s okay.” Deku cooed, a harsh thrum of heat and excitement racing through him, making him feel dizzy, “It’s not hard at all. Just get on your knees for me, okay?”

“O-Okay.” Izuku mumbled, clumsily lowering himself down onto his knees. 

Deku didn’t bother waiting. Grabbing a handful of his hair, he tilted his head back, leading the tip of his cock to his plush, plump lips. Izuku’s eyes widened further. He didn’t flinch back – a good sign. Glancing up at Deku, he audibly swallowed, reaching up with one hand to carefully wrap it around Deku’s length. Smiling widely, heat burning in his cheeks, moments away from just shoving his cock into that tantalizing mouth, Deku pressed a thumb to the curve of his chin, gently opening his mouth. Izuku connected the dots right away. Breathing shallowly, he needed no further prompting to stretch his mouth open wide. It was still such a small hole but that didn’t worry him. After all, all Izukus were massive masochists. Wanting to go ahead and prove that to this little Izuku, Deku clamped down on the sides of his heads and thrust forward, sliding his cock between those pink lips, pushing in deep. Incredible tight, wet heat surrounded him. A bolt of pleasure radiated up his spine, bursting in his head as a bright explosion of sparks. Izuku let out a loud, muffled moan. Heavy lidded, hazy eyes gazed up at him as he pushed in even deeper. He gurgled loudly when the head of his cock hit the back of his mouth then slipped down into his throat. Drool poured down his throat. He clung to Deku’s hips. 

“Tastes good, doesn’t it, Izuku?”

Izuku shuddered. Strengthening his hold on his head, Deku began to move, rapidly pumping his hips to repeatedly drive his cock into that wet heat. So tight! Izuku’s mouth was so small – it was perfect! He was clumsily sucking him, rubbing his cute little tongue against the underside of his dick as he repeatedly pummeled into his mouth. Pleasure rolled through him in thick, heavy ways. Precum poured out of the slit – he could feel Izuku swallowing it. 

“So eager!’ Deku laughed, “Don’t worry, I’ll give you every drop of my milk. When I’m done, you’ll have a quirk that’ll be beyond your wildest imagination.”

With that promise, Izuku began to suck even harder. He couldn’t move with Deku holding him but that didn’t stop him from trying. It was such an adorable thing that Deku released his head, allowing him a little more leverage. Fuck… he usually lasted so much longer than this but this Izuku was just too damn cute! Keeping his gaze trained on Izuku as he haltingly bobbed up and down, his plush lips sliding over his thick, veiny length, Deku held on for as long as he could but it just felt so damn good. Curling his fingers into Izuku’s hair once more, he yanked him down, forcing him to take every last inch. His balls thumped against his throat. A loud moan rippled out of his panting mouth as his cock swelled up even bigger then, with a hard twitch, a flood of cum was pouring down into Izuku’s stomach. He wailed loudly, his thin, small body visibly shuddering as he swallowed it all down. Unsurprisingly, cumming inside of this adorable boy’s throat was incredible. Heavy, brilliant sparks of pleasure raced out from the base of his belly. His entire body was tingling. Fuck… he had fucked a lot of younger versions of himself but this one was quickly turning out to be one of the best. 

Just as Izuku was swallowing down the last drop, Deku slipped free of his sloppy mouth. Stepping to the side, Deku dropped down onto his butt, grinning widely. That was good but he wanted something even better. The Izuku of this world was a virgin…well, not for much longer. Just like he had done with so many other versions of his younger self, he was about to introduce Izuku to something that would change his life. Pulling a handkerchief out of his back pocket, he quickly dried his cock off, wiping away every last trace of Izuku’s saliva. Izuku gazed at him, dazed and obviously sucking on his tongue. Little did he know that he was about to give him something even sweeter. Grabbing Izuku’s arm, he yanked him into his lap. Their chests collided. He wrapped his arms tightly around him, his hands traveling down to give his plump ass a firm squeeze, earning himself a wet gasp. Izuku pushed his butt back into Deku’s hands, grinding against him. Fuck, this kid kept getting better and better. Deku didn’t bother with trying to get his pants off – way too much trouble when he was dying to be buried inside him. Instead, he grabbed the seat of his trousers and yanked hard, easily ripping the fabric to tatters, exposing that gorgeous butt. Izuku gasped softly, his head craning around to try to look down at what Deku had done. Taking advantage of his attention being elsewhere, Deku dropped down onto his back. 

Grabbing Izuku’s hips, he lifted them up until his dry, tight, virgin hole was hovering right over his cock. Smiling, he tapped his finger against Izuku’s hot, sweaty skin, “Just need a little bit more, Izuku. You’re not gonna complain, though, are you?”

“N…No…” Izuku gasped, staring down at Deku with that gorgeously dazed, wanting expression, “More….More…give me more…I want…”

“Then, put it inside yourself. Let gravity do the work.”

Swallowing hard, Izuku nodded shakily. Bracing his hands on Deku’s chest, he lined his hole up perfectly to the tip of his cock then dropped down. Since he was completely dry, only the very tip managed to slip in. A shudder wracked his thin body. Mouth hanging open, drool pouring down his chin, Izuku did as he was told, letting gravity do the heavy lifting. Slowly, he sunk down on Deku’s cock, taking in inch after inch of his throbbing, massive cock. The burn, the friction of those dry walls crushing him was astronomically good. Halfway down, Izuku visibly came – throwing his head back, every muscle in his body tensing up, a loud wail slipping free from his saliva drenched lips. He kept sliding down further onto Deku’s cock until, after what felt like an eternity, the plump mounds of his butt were pressed snuggly to his pubic bone. Tongue hanging out of his mouth, panting heavily, Izuku shakily lifted his head to gaze down at Deku. 

“C…Can I-“

Deku gave one of his asscheeks a playful slap. His heart was beating like crazy. He couldn’t remember the time he felt this fucking good. It was taking all of his concentration not to cum right away. There was a little bit of wetness inside of Izuku. Sliding his head further down, he pressed the tips of his fingers to his swollen, stuffed full hole. When he pulled his hand away, there was a small amount of blood on his fingers. Not enough to be worried about but enough to know that Izuku was going to cum again the moment he moved. That was just fine with him. Clamping his hands down on Izuku’s hips, he easily lifted him back up, loving the way his expression changed as the veiny cock inside him scraped across his abused insides then slammed him back down. As predictable, Izuku came right away, squealing loudly as he violently shook in Deku’s hold. Digging his blunt nails into Izuku’s soft, smooth skin, he repeated the motion – raising his small, shaking body up then slamming him back down. A familiar sensation began to build in the small of his back, slowly spreading out to his stomach and chest. Deku moaned softly, his eyes fluttering shut. His quirk…the one piece of it that he was giving to this adorable cutie was ready to be passed on. 

He hadn’t lied completely to the kid. He wouldn’t be quirkless, after this and he would have one hell of a powerful quirk in his possession but he would never be as powerful as him. All Might could use this quirk up to 50%. This Izuku would probably be one of the more powerful ones – wouldn’t surprise him if he managed to hit 100% but Deku… there really wasn’t a percentage for him. After all, he was the first, the beginning. He could give little pieces of his power to a trillion Izuku’s and still not be any less powerful. 

“Cum-!” Izuku whimpered, “Cumming-! Cumming-!”

“Me too.” Deku laughed, “I’m giving everything to you, Izuku. Promise you’ll be the best Hero this world has ever seen.”

“I pr-promise!” Izuku wailed, “I promise! I promise! I-!”

Ah, he was kind of bummed that this was over. He could have easily spent the next few hours fucking this adorable kid but…he was at his limit too. He could feel that small piece of his power thrumming in the depths of his stomach. It was ready to be passed on. He…he couldn’t hold back anymore! Grinding his teeth together, slamming up into Izuku’s tight, incredible hole, Deku choked out a harsh groan and came, spraying his jizz all over his spasming insides. At the same time, Izuku let out a sharp, wailing scream. A rush of warmth flooded down from the center of his chest to his crotch before gushing up his urethra then disappearing into Izuku’s body. It was always a strange thing to witness – the passing on of this bizarre quirk. Izuku’s stomach began to glow. It was faint at first but as he pumped more and more of his seed into him, the glowing became even brighter. It was always kind of remarkable that his younger selves’ bodies weren’t completely destroyed by suddenly having this quirk implanted inside them. 

As quickly as the glow appeared, it vanished. Izuku shuddered, let out a shaky breath then slumped backwards, falling to the pavement with a soft thumb. Deku’s cock slipped out of his ass. There was a small amount of blood on his thighs. It was going to be difficult for him to sit down for a while. Not that he thought the kid would care. After all, he was now in possession of an incredible quirk. Smirking, Deku got to his feet, tucking his cock back into his pants. Now was when things got weird. Up until this point, things were pretty predictable but after he passed on his quirk? There was no telling what would happen. Just as his curiosity was getting roused by the possibilities, there came a sound from behind him. A sharp, rasping gasp. Fuck, someone had found them, which meant it was time for him to go. Stepping to the side, he easily blinked to a nearby rooftop. Just in time too. Right as his foot was landing on the tiles, there came an enraged roar of someone screaming, followed by a loud boom. Deku blinked hard in surprise. He’d recognized that voice anywhere. K-Kacchan?! This world…it really was a strange one. 

-

Perched on the edge of the rooftop, his cheek resting in the curve of his hand, Deku gleefully watched as Izuku walked away from a pale, sputtering All Might. Standing closeby was Kacchan, his hands shoved deep in his pockets, gaze darting all over the place. He’d been glued to Izuku’s side since finding him yesterday. Despite Izuku’s repeated assurances that it wasn’t rape, Kacchan had taken one look at the blood and wouldn’t believe anything else. Deku found it cute and Izuku, noticeably, liked the attention he was getting from Kacchan. The kids had better hurry up, though – there was only a little bit of time left before the entrance exams at UA. Trailing after him, his bony hands held out in front of him like a zombie, All Might kept trying to say something but it was like someone had a hold on his throat. Everything came out as a gurgling mumble. While he couldn’t blame him for being shocked – the meek quirkless kid who, before this point, had been working so hard to get One for All but now, was coldly telling him he was no longer interested – it was a fucking delight to see him stumble. After all, who would turn down the chance to get the, supposedly, greatest quirk in the world from the, again, supposedly, greatest hero in the world? 

That was a question All Might would never have answered. Judging from the cold way Izuku glared up at him over his shoulder, sternly telling him not to follow him anymore, it didn’t feel to outside the ballpark to assume the kid thought that All Might was holding out on him – promising this immense power when, really, he only had a small percent of it. Which was both true and untrue. All Might had no access to anything beyond the small percentage he already had. Was it possible for him to get it? Yes, but that would require him to do stuff that someone like him could never fathom doing. Deku, on the other hand, was more than willing to do anything to become more powerful. Could he have explained that to Izuku? Yep, but he wanted the kid to despise All Might’s guts. Made things a whole lot easier down the line. 

Brushing off All Might’s repeated attempts to talk to him, Izuku briskly walked off, Kacchan right by his side, their shoulders practically bumping. Deku watched them until they disappeared into the distance before turning his gaze back to the shocked All Might. Did it hurt? To be so suddenly rejected by the kid he thought was the one? It usually did but every world was different. Getting to his feet, Deku blinked to another rooftop. Still walking close together, Izuku and Kacchan were quietly talking with one another. He didn’t bother getting closer to hear what – it wasn’t any of his business. As he watched them head towards UA, he wondered who Izuku would pick in this world. During his time at UA and his subsequent rise through the Pro ranks, he would meet a lot of people who would fall over themselves for a chance to be with him. The corners of his lips curled up into a slight smile. There were only a handful of Izukus that he kept an eye on after he passed on a piece of his quirk. This one – this adorable cutie who was so forward, so honest – was definitely one of them. 

He could wait to see how his story played out.