Its soft BakuDeku hours: Pro-Hero Omega Izuku is boarder line infertile and always wanted a kid of his own but never allowed himself to be in a relationship or think about having kids due to his own insecurities. He pushes himself while working to distract himself until one day

While he was out on a mission with Kacchan they save a a bunch of people from a collapsing building that a villain with a strong quirk attacked. They rescue everyone they can out of the debris and when Deku thought he rescued everyone he heard the cries of a baby coming from

around the corner. He looked at Kacchan to see if he's paying attention but he's tending to people. Slowly, Deku rounds the corner and he finds a baby being tightly held in a woman's arms

Izuku rescues the baby and they assess all the damage that's been done.

"I'll drop the baby off at the shelter, Kacchan. Don't worry," he says while holding the crying kid in his arms. The tiny hands clutch at him and there was an instinctive pull to hold the small one close

Katsuki doesn't think much of it, and leaves to help other victims out around the scene but when Izuku got to the shelter to file the paper work he couldn't hand over the child to the woman

He looked down at the large brown eyes and felt something stir inside of him with need and want. The woman looked at him curiously and he shuffles backwards to tell her to give him a minute.

The longer he looks at the baby's face he finds himself falling softly in love

~~~~~~~~~
Katsuki didn't think much about Izuku taking the baby to the shelter. He knew Izuku was much better with kids than him. The nerd was soft and all that shit.

A month goes by and he finds Deku acting strangely happy yet really distant from everyone

He watches carefully as Izuku leaves work, shuffling quickly past everyone. He also notices how he asks All Might for a small pay bump but doesn't give a reasoning as to why.

For some reason the curiosity is strong as to what type of secret would the nerd be keeping /now/?

So he follows him one day. There was a lack of calls in and his Alpha was telling him to figure out what the Omega could even be hiding, especially after the OFA secret they shared.

What he wasn't expecting to see was fucking Deku waltz into a baby story

"The hell are you doing baby gonna diapers, Deku?" He hisses as he corners the omega in the corner of the store. The nerd jumps out of surprise, not expecting to have been followed.

Izuku stammered as he grappled at the various items his hand, like he had been caught red handed

"K-Kacchan! What are you doing h-here?" Izuku harshly whispers, holding a carton of baby food was too tightly.

"What am I doing here?" Katsuki says unimpressed. "I aint the one buying food like I have a litter at home." He waits for Izuku to retort but instead Izuku pauses

Red eyes widen slowly when Izuku didn't deny the statement. He waited several more moments but as the silence stretched out Izuku's face looked more and more guilty.

"Deku." He says firmly. "You don't have...kids at home do you?"

Izuku makes a strained sound in his throat

I wrote this deadass half asleep, excuse any typos, but I shall continue this in the morn

Good morn! I’m back!

Katsuki stared in disbelief at the tiny human sleeping in Izuku’s arms.

“I-I couldn’t give her away, Kacchan. Not to an orphanage,” Izuku whispered, his eyes never leaving the baby he was rocking in his arms. “I adopted her legally after her mom passed.”

“Do you even know how to take care of a kid, you dumbass?” Katsuki hissed harshly but Izuku just shook his head at him.

“No, but I can learn.” Izuku replied back with the damn fiery determination Katsuki has seen over and over again in him.

“Does anyone else know?”

“I told Shouto...he’s been helping me baby sit.”

“You told the damn half and half bastard before you told me?” Katsuki felt his inner alpha instantly bristle. He didn’t know why but it felt insulting that Deku would go to icythot before him and he nearly snarled.

“He just picked up quickly,” Izuku huffed, glaring at him for the aggressive pheromones he was giving off unwillingly. “He’s just observant. It’s not a big deal.”

“Deku, it /is/ a big deal,” he sighed, trying to calm down.

“That’s a whole person you gotta take care of and last time I checked I was the one reminding /you/ to make sure you eat full fucking meals.”

“I can’t give her up, Kacchan,” Izuku’s voice was soft as he pushed a small brown curl out of the baby’s face. “I can’t do it.”

Katsuki pauses as he looked at Izuku carefully. The damn nerd /wanted/ to be a parent & it made something inside him twist slightly seeing Izuku hold the baby with such care.

He sighed & took a seat next to Izuku on the couch. “What type of shit does a baby need?” He grumbled.

~~~~~~~~~~~~
A month goes by and Izuku makes sure start learning how to balance his life. Having a new born baby added into the mix with hero work was much harder than he expected but with the way Aimi looked at him that’s all he needed to keep going.

However, he noticed Kacchan hovering over him slightly as time went on.

The grumpy blond would come to their agency with supplies he needed or food or even clothes. He’d drop them on his desk wordlessly and then hover slightly asking him how he was doing

Soon the alpha was coming to his home under the pretenses of ‘making sure he wasn’t fucking up’ & bringing over food & baby supplies. Izuku watched curiously as his childhood friend slowly made himself at home in his apartment.

Before he knew it, Kacchan was a baby expert.

“You’re supposed to hold her head like this, dumbass.” Or “Don’t put her in IcyThot’s baby hero clothes. Use my merch at the very least.” Were common phrases being tosses his way.

Shouto shortly stopped coming over to baby sit and Kacchan was taking the wheel full force.

“Thanks for putting her to bed, Kacchan,” he whispered after coming home after a long day.

“Ain’t a big deal, Deku.” Katsuki replied, motioning for the green haired man to take a seat on the couch. “Someone has to make sure you and the kid stay alive.”

“Heh, thanks,” Izuku gave a bright smile. “You’d make a good dad, Kacchan.” There was a long stretch of silence before red eyes looked at him with something glistening in his eyes.

“…I’d make a better mate.”

I have to go to class but I'm debating on which route to take this lmao Should this get smutty or stay soft?

[Soft smutty - both win!]

“M-Mate?” Izuku says baffled, leaning backwards, confused. Green eyes were wide while red ones looked soft yet confident. Like Katsuki cared.

“C’mon. I know you think so.” Katsuki whispered. Izuku looked off to the side at the room that held Aimi.

Kacchan was right really, he did think so. Watching the alpha help around his place the last two months and see such the usually explosive man handle the infant with care stirred his omega in ways Izuku never allowed himself to feel.

But it was also Kacchan. Someone he trusted.

“You have been really great these past few months...” he admits. He always liked Kacchan but never voiced it out loud, too afraid of putting himself out there.

“I can be more than great if you let me,” the raspy voice whispered low. “It feels nice. To be useful for you & Aimi.”

“You don’t care about me being basically infertile?” Izuku says bitterly.

“Of course not.” Katsuki had to stop himself from rolling his eyes because no, he didn’t give a shit. But it wasn’t a secret that Deku had issues with a past boyfriend over his fertility levels.

“I’ve just been thinkin’” he says, hushed. He leans in carefully towards Izuku’s space and watches as the pink tint in his cheeks becomes darker and his scent becomes sweeter.

“We’d make a good team all around, hah?” He smirks when Izuku slowly nods, eyeing his lips.

“We do make a good team.” Izuku agrees. “I-it would be nice to have you...here with us.”

Katsuki smiles this time. No smirk, but an actual smile. “I wouldn’t have it any other way, dork.”

Before Izuku could retort back, Katsuki leaned in and sealed his lips with his own.

The greenette’s heart fluttered out of his chest as he allowed himself to be swept away by the warmth of the alpha—no. The warmth of /Kacchan/ kissing him so softly.

There was no one like Kacchan. Someone who was rough yet gentle and caring all at the same time.

The kiss progressed and both hero’s lost themselves in the new warmth they had cultivated. A silent longing moan slipped past Izuku’s lips and Katsuki smirked into the kiss.

“Shh, don’t wanna wake our pup now do you?”

“...Our pup?” Heat shoot straight down Izuku’s spine.

[NSFW from here on]

“Yeah, Deku.” Katsuki smirked into the kiss. “Our pup.” When Izuku’s scent grew sweeter and more aroused Katsuki felt himself nearly growl.

“You like that thought, huh?”

Izuku nodded furiously. His omega sung happily at the prospect at having a family

They sunk deeply into the couch together & Katsuki dipped his hand low in between Izuku’s legs.

“Is this okay?” He whispered rubbing into Izuku’s sensitive areas.

“More than okay, Kacchan.” Izuku replied, opening himself up more.

Everything about Kacchan was perfect to him & this was what he never allowed himself.

Katsuki eagerly wedged himself in-between the thick legs and swallowed all the little gasps and moans that left from the other hero. He slid off the greenette’s clothes with a needy quickness.

The smell of slick slammed into him ignited a heat that started to coil inside of his abdomen.

“I wanna give you fuckin’ everything, y’know,” the alpha hissed, driving his fingers deep into the slick wetness of Izuku.

He pumped them in and out quickly, hitting the pleasure button inside of Izuku rapidly without mercy.

“I wanna give you a home, I wanna make sure you and the pup are safe,” he continued on as Izuku felt rapid fire electricity shoot down his spine.

“I wanna give you food and just any shit that you could possibly want, Deku.”

Izuku curled his toes as the alpha kept going, adding in fingers and stretching him out. The heat in his body built up higher and higher burning harder than he’s ever felt.

“I want your knot too—” Izuku strained out through a moan, curling his toes & rolling his eyes back. Fuck. Kacchan was so perfect. He needed him, he wanted to feel so full of Kacchan.

“You want my knot?” Katsuki hissed.

“I want your pups,” Izuku moaned out making the blonde growled deeply. “Give me your pups, Kacchan, I want a family—ah!”

The greenette was suddenly flipped over & the smell of burnt wood & forest filled the air as Katsuki’s alpha let of intense pheromones.

The alpha stripped away his clothes, throwing them on to the floor in a spilt second.

Izuku moaned as he felt the wide girth of Katsuki’s hardness stretched him out and everything inside of him started to hum and purr with satisfaction.

The alpha jerked his hips forward with a loud snap and pushed his thick length all the way in.

“Gotta be quiet, Deku. Our pup is sleeping. You wanna be bred, right? You want more pups?”

“Yes, yes. I want more, please!”

He keened softly as the alpha started thrusting as a brutal pace, losing himself into the moment. Izuku rolled his eyes back as he was filled over and over again and his body was pushed with limits he didn’t know.

A rough hand buried itself in his hair as Katsuki laid on top of him, using off all his strength to fuck him into the couch like he was on a mission to get him pregnant right then and there. Hot hands worked over Izuku’s chest, pulling and pinching at his sensitive pink buds.

The hand in green curls tightened snapping his neck up and Katsuki’s breath tickled his ear.

“I’ll give you more, Deku. Fuck—gonna give you all the cum this ass of yours can take.” The deep voice rasped out in a sinful tone.

“I wanna big family, Deku. Means we gotta do this often. You want that?”

“Yes, yes!” Izuku cried as he felt the swelling of a knot push against his entrance & rapture exploded in his chest. Everything started to feel insanely hot and it was getting too much, Kacchan was so big—

“Aimi needs a little sibling, right?” The pace picked up faster and more desperate as Katsuki pounded into him recklessly. Izuku felt himself getting close to his edge as he grappled for the couch trying to keep quiet with every thrust and jerk of Katsuki’s cock diving deep.

“Yes! Alpha, please. I-I’m gonna cum—”

Teeth scraped as his neck and Izuku titled his head to the side in submission. The blond alpha’s nostrils flared at the motion and he drove deeper and harder into the smaller body.

“F-Fuck, I’m gonna knot you!”

The Alpha above him growled loudly as he released himself inside of the omega and his knot pushed into the tight entrance, getting sucked in like he belonged. The pressure caused Izuku to tip over completely, his orgasm ripped from his body fiercely.

Izuku’s voice cracked in a strained moan as he buried his face in the couch and Katsuki held on with a bruising grip to his body. Warm cum decorated the inside of his body, filling him up. He was so full, he felt so perfect and full with Kacchan deep inside of him.

Izuku wiggled his hips ever so slightly making Katsuki hum deeply in his chest.

"Sorry 'bout knotting you."

"No, don't be, this feels perfect." Izuku smiled as he turned to the side to look at Katsuki. "I think we're going to make a good partnership."

Kacchan smiled back.

~~~~~~~~~~~~~
{2 years later}

"Dude I can't BELIEVE you got him pregnant with twins." Kirishima laughed as they sat inside the deliver room. "What kind of alpha shit you got going on?"

The blond just smirked proudly holding one of the curly blond new borns in his hand.

Izuku laughed happily as their adoptive daughter eagerly paced around happily, singing about getting more siblings.

"I wanna name them!" Aimi sang out as she stared at the two new borns. "They're so chubby and cute!"

Katsuki leaned in to lay a kiss on Izuku's forehead, both of them holding a twin with everyone happily taking pictures of their new, large loving family.

"I love ya, Deku."

"I love you too, Kacchan."

~FIN~

I’m gonna be making this into a multi chapter come November! Keep a look out :)

This is officially a thing! :) I hope you enjoy! First chapter is up of "Fumblehood"

https://archiveofourown.org/works/21263306/chapters/50626694