Chapter Text
Enji is sitting at his desk with his head barely held up by his arms when he looks at the stack of paper cluttering his workspace like the damn plague it is. It's almost been a week and Rei hasn't returned from her little trip to her friends’ place and it’s starting to piss him off big time.
She probably does this on purpose, Enji thinks; none of the things she does are without thought and she probably knew that as soon as Natsuo would turn out less than what he had hoped for, it would mean finding herself back underneath him in bed sooner or later. And apparently, later is what she seems to be going for with this—not that it's too much of a bummer with how bad of a lay in bed that woman is, but they're certainly still wasting precious time.
It's a shame, really. Enji did have high hopes for Natsuo, he really did, but now that he knows that the boy is an omega, chances of him becoming a hero as strong and competent as All Might and even surpassing him have nearly dropped to zero. Or… well, it's probably not completely at zero; there have been a couple of famous heroes in the field who made it big despite being omegas after all. And Enji certainly managed to make it far too despite being an alpha dealing with regular ruts that would distract any other professional hero. But at the same time, Enji just can’t see how Natsuo would be able to suppress it in that kind of field. It's too much of a gamble.
It's honestly embarrassing for him to have his son be an omega. Out of all things. Omegas in and of themselves are pretty rare in the population and he mostly heard of them being girls. But omega boys? That's certainly something Natsuo is bound to get bullied for at school. Or hell, maybe his entire life. Enji just knows it. It's not good for marketing. It's not good for professionalism. It's simply not suitable for what he had in mind for his future.
In fact, it's only a matter of time before his boy would turn into a blubbering, horny whore who’d probably beg any stranger to fuck him up the ass in a few years, and Enji simply is not ready to deal with that.
The thought of it alone is revolting. He needs a new child now. And he needs Rei to be home for that.
The night is still fairly young when Enji gets close to the end of the pile of paperwork on his desk, only to be inevitably distracted by the sound of Natsuo crying out and weeping several rooms over.
Almost out of pure habit alone, he dismisses it and ignores it at first before he remembers that Rei isn't even home to take care of that for him. He still mulls over whether to go and do anything for a moment though, counting that perhaps one of his other kids will hopefully wake up and go check on Natsuo themselves, but none of that seems to happen. He waits for a moment listening to the crying continue, his fingers pressed against his temple in absolute distaste for having to do this himself. But before he even gets the chance to get up from his chair, Enji’s nostrils flare up. Something suddenly shifted in the air— something that immediately sets off a primordial sense inside of him. Something that gets his cock rock-hard at an instant.
It's the familiar scent of an omega in heat; Enji recognises it immediately since he's smelled it a couple times in his school days and on some other more recent days here and there in the streets. But this smell is far more intense and fresh than any omega’s heat that he’s ever picked up on before. It feels like he’s being smothered by the smell. Assaulted. Like the scent of a young, plump flower opening its bud for the very first time, begging for a bee’s deadly sting.
Enji raises a hand to cover his mouth for a moment as the whimpering and crying continues.
It couldn't be Natsuo, could it? The boy is only three years old after all and omegas usually aren't supposed to have their first heats before they hit puberty and are ready to become pregnant. So it couldn't possibly be…
Right?
He hears Natsuo’s screams ring out through the entire house again, calling out for anyone to help. His mother. His siblings. His father.
“Daddy!” Natsuo whimpers, stretching the word long and wide as he calls out into the void. For him.
It’s Enji’s inner alpha that suddenly starts to bark and grunt on his way towards Natsuo’s room. He walks with his arms stretched out and flexed at his sides, his muscles tense and his mouth watering as images of Natsuo’s pink omega hole start flashing up in his mind, stretched and twitching, empty and filled. His fresh, little omega slut. His his his.
Enji nearly howls when he opens the door to Natsuo's room, his eyes rolling far back into his head and his knees almost giving out when he's hit with the full force of Natsuo’s heat.
“D-Daddy, I’m scared. I’m… I’m burning. It’s so hot, it hurts, it hurts! Please, Daddy, help!” Natsuo whimpers, squirming and writhing on top of his sheets.
Enji doesn't even remember pulling his own pants down before he finds himself standing over Natsuo’s futon with his cock and ass out bare. He didn't even close the door behind himself.
“Hold still,” Enji demands in a firm, hot tone, almost as if on autopilot. He bends down and gets on his knees before pulling Natsuo’s little shorts down along with his tiny underwear. He makes sure to also relieve Natsuo of his little shirt that he seems to have tugged on repeatedly but failed to get off. “Hold still and I’ll stop the burning. Hold still, understood?”
Enji doesn't even wait for his boy to respond. His cock twitches and leaks in delight the moment the tip makes contact with his boy’s slick omega hole, but as somewhat expected, no matter how hard he tries to push inside, his cock is just too big for the boy to take, especially with how Natsuo is clamping down in absolute shock.
“Ah, you're hurting me! It won't fit! It hurts!” Natsuo repeats through whimpers, and Enji nearly wants to punch the kid for whaling this loud when he’s already told him to stay quiet. He doesn't, though, because in the end, he also knows that Natsuo is probably right after all.
No matter how desperate his inner alpha is to get inside that hole, he's too big and Natsuo too small and tight. But at least Enji knows that he can fix the latter.
He grunts out of frustration as he pulls back with an aching and blushing cock. He gets a hold of one of Natsuo’s legs and shoves a finger into that tight hole instead, at which Natsuo immediately transitions from whimpering into equally loud moaning.
Dirty little slut.
“That better, boy?” Enji asks.
Natsuo nods violently. “Y-Yes… ah, feels better, but… ah, it’s s-strange, Daddy…”
“Sexy little bitch… Who told you you could go into heat this early anyway? Couldn't wait to get dicked down, huh?” Enji says and even manages to shock himself by what's coming out of his mouth.
Did he just call Natsuo sexy?
It's like he can't tell what his own thoughts are anymore. As if part of his mind is being taken over by whatever that voice in his head is that sees his three years old son and immediately thinks of filling, stretching and breeding. It's almost hard for himself to admit, but watching his thick fingers stretch his boy's young cunt, how Natsuo’s little cock twitches and Natsuo sighs out in pleasure each time his rim gets stretched around Enji’s thick knuckles, it suddenly is the hottest fucking thing Enji has ever witnessed. In fact, so much so that it's almost torture that his fat cock isn't already hilted deep inside and stretching that hole even further.
“D-Daddy, it… I feel w-weird. I think I’m going to pee.” Natsuo quivers around his fingers, but the kid’s calmer voice indicates that it's already working. That his finger is already stopping the burning.
Enji hisses and growls through gritted teeth. He doesn't stop finger fucking Natsuo. Goes even deeper, even faster. “Hold it,” Enji just says like it’s the easiest thing in the world before he pauses for a moment, yet without stopping to finger his boy when he takes a deep breath. “I’m going to pull my fingers out now and then fuck you, you hear? I’m going to fuck you,” he announces.
Enji doesn't even pull his fingers out before he's already trying to push his cockhead into Natsuo for the second time. He fingers him with the same pace as before and scissors his fingers apart to make an opening big enough for his cock before…
“Fuck, fuck, fuck!”
It's Natsuo who screeches in sync with Enji’s moans when Enji’s cockhead pops inside of him and Enji nearly sees stars with how tight Natsuo feels around him. Enji just covers Natsuo’s mouth, seeming to blank in and out of consciousness as he soberly watches his length slowly disappear more and more into his weeping boy.
“Shut your fucking mouth already, you whore! This is good for you!” Enji shouts and watches as Natsuo’s tears soak into the sheets as well as blood slowly starting to trickle out of his kid’s hole.
It takes a few moments for the man to finally establish a steady rhythm to plow into his boy, but by the time he completely bottoms out, Natsuo has already gone completely silent, his eyes lazy and mouth hanging wide open without the need of a hand covering it anymore. Completely broken in.
His cock is so big that it makes Natsuo’s stomach bulge double its normal size with each thrust, and Natsuo actually seems to enjoy it too. Or at least that's what Enji gathers by the way Natsuo’s tongue is sticking out of his mouth.
“My omega bitch. My three year old omega bitch. Fuck yeah, that's what you are. Do you like being Daddy’s little omega bitch? Do you like when I fuck you, Natsuo?”
“Y-Yes… Yes, Dad...dy… Thank you, Daddy,” Natsuo says without even knowing half of the words his father is saying. Just knowing that it’s stopping that agonising burning inside of him.
At this point, both Enji and Natsuo are so lost in their own sick pleasure that the world around them nearly falls apart. Enji remembers hearing Fuyumi and Toya at some point, hearing and seeing them from the corner of his eyes as they ask what he and Natsuo are doing in terrified voices. Their words repeatedly fall onto deaf ears until they give up and leave, pulling their heads out of other people’s business. As they should.
It's early in the morning and when the sun is shining into Natsuo's room when Enji finally cums after long repeated dives into his boy. And it’s like the most intense pleasure on earth is taking over his entire body.
He definitely grunts loud enough to make Fuyumi and Toya startle in their own rooms as he slams his sloppy, bloody cock deep into Natsuo for the grand finale before… something occurs that's never happened to Enji before.
With each and every hot gush of cum unloading into Natsuo, Enji feels his cock swell up at the base until not even Endeavor’s might could separate the alpha from his mated lover.
“F-Fuck— Baby boy, I’m— fuck—”
It's a pleasure that Enji has never felt in his entire life, making him wonder if any of the orgasms he had before this day could even be called orgasms in comparison to this.
His body trembles all over, his arms and legs now actually giving in as he nearly crushes Natsuo under his massive weight and manages to push his knotted prick even deeper into his kid.
It's like he's losing complete control of his body. His breath, his heartbeat, even his thoughts won’t obey him. He just keeps cumming and cumming, feels his cock pulse and gush more and more into Natsuo seemingly without end. And whenever he does think it should end, it simply doesn't. It won't.
It's only when he hears Natsuo’s muffled coughs underneath him, when he feels splats of wet coughs hit his sweaty pits, that he realises that Natsuo is still stuck underneath him, desperately trying to crawl out from under his father's weight.
Enji quickly uses his arms to push himself off the ground again, watches still in trance as his little boy cries and coughs, both blood and cum spurting out of Natsuo’s mouth and nose as he fights to escape his father and fails repeatedly.
Enji groans in pleasure at each additional tugging sensation onto his knot, feeling one more orgasm after the other being forced out of him the more Natsuo struggles and pulls.
Enji just wants to bend down to kiss him. To shut him up with his huge tongue shoved down his throat and thank his boy for all the pleasure, yet Natsuo is so tiny that he barely reaches the boy’s forehead to place a kiss on it.
He's heard of what it's like for an alpha to mate with an omega way back in high school, but this isn't what he had imagined.
It doesn't seem quite real to him. Doesn't make sense to him. None of it. He's looking down at this kid almost lucid, sees how much Natsuo’s struggling around his cock and yet all he wants to do is protect and love him to the end of the world. His omega. His his his.
It takes him a moment before Enji regains some sense of presence again, like a veil that's been covering his eyes is being pulled off.
He silently grabs a hold onto both of his boy's legs, places a kiss onto Natsuo’s forehead and starts another, more gentle rhythm (as much as his knot allows him) that he keeps up for a while.
He manages to tickle a few more orgasms out of himself throughout the morning and gets lost in the pleasure…
Until all hell breaks loose when Rei comes back home and finds them like this.