Kirishima was on cloud nine as he walked though the halls of the school. he'd just gotten a98 on his last test, He was at the height of his powers AND he had a blond cutie pie for a boyfriend and a big baby.
for a daddy dom like Kirishima it was like getting triple 7's at a slot machine, even though there was ONE slight problem with his cutie pie big baby.
it was that his big baby who could be loving and sweet and such a widdle cuddle bug in private..was a big brat and a total bully in public.
If you hadn't of guessed as much by now, the baby in question was Katsuki Bakugo, Who as Kirishima looked out one of the hallway windows he say him bullying anther student.
'Little man..I thought we talked about this.' Kirishima thought and frowned, crossing his arms as he watched the scene. 
He was NOT a fan of his little sweetheart being a bully and had tried everything from washing his mouth out to spanking his bottom bright red and even tried bribing the brat, but nothing seemed to work. 
Slowly thought as he kept watching, a plan formed in his head. it was a evil plan to be sure, and one that might just break the little guy, but as a responsible daddy he knew it was his duty to teach his widdle guy right from wrong.

Meanwhile, not knowing he was being watched, Katsuki was having fun as he gave a third wedgie to glasses wearing student. he hadn't even bothered to learn the nerds name, he'd just felt the need to blow off some steam and the nerd had been the closet target.
"S-Stop this o-or I'll-" the nerd whined and whimpered, lifted in the air by his hello kitty briefs and Katsuki snickered.
"You'll what? wet your panties? Tell a teacher? go ahead~ But if I get in trouble because of you you'll WISH for something as kind and loving as I'm doing right now~" Katsuki said and then holding the geek up with one hand twirled him with the other.
with the geek all twirled up, Katsuki let him spin and held out his palm so the geek got slapped every rotation.
"Geez stop hitting yourself on my hand nerd!" Katsuki laughed and when the nerd was all dazed and confused, hiked him up higher and then dropped him to the ground.
Hilariously at least to Katsuki, as the nerd whimpered and sobbed, the front of his pants started to darken and then the geek was wetting himself.
"Pffft, Are you pissing yourself? what a BABY!" the blond bully laughed loudly, even though he was the last person who should be teasing someone else.
"Maybe you should ask your mommy and daddy to get you some huggies, LOSER!" Katsuki chuckled, and again, considering he was at the moment wearing a power ranger pull up under his own pants, he had ZERO room to talk.
Still, he decided the geek had had enough and walked away, whistling and feeling good and having NO idea of the hell that would be waiting for him all too soon. 

That night while snuggling with daddy, Katsuki was in his normal daddy time attire (Read: A thick massive white disposable diaper and a t-shirt reading daddies little stinker, and sucking on a paci)
they were watching one of daddies shows but since it wasn't a cartoon Katsuki basically tuned out of it, thinking about how tomorrow was one of his rare brief days and looking forward to it.
it wasn't that the blond didn't like his pull ups or his diapers (Clearly he loved them) but well, the pull ups just sorta felt close enough to his huggies that sometimes Katsuki would almost boom boom in them before catching himself.
Daddy also had promised if he could prove he didn't need his pull ups by keeping his undies clean 10 times in a row (and tomorrow was day number ten!) then he could stop with the pull ups at school anyways.
with dreams of big boy undies during the day Katsuki suckled extra hard on his paci, not registering the weird taste on it and the fact he was sleepier then normal, and just snuggled into daddies side and closed his heavy eyes for a second.

when he opened them again he was being dressed by Kirishima and it was morning. 
"Hey sleepyhead, welcome back to the world of the living. you conked out HARD on me last night." the red head chuckled.
"I..I did? huh..Weird." Katsuki said and sat up. 
he felt a little wonky still, but gave a yawn as daddy finished getting his shirt on him, his socks, undies and pants were already on and a glance at the clock told him that he'd super slept in, they were gonna have to boogie to get to class on time.
"Sorry I conked out on you, wanted to play with you." Katsuki said and got up, pecking daddies cheek with a smooch and reached down for his school bag.
"hey it happens. maybe my cute big baby needs to start taking naps." Daddy said and winked.
"heh, maybe."  Katsuki agreed though the thought brought a blush to his cheek.
"something to talk about later, for now, let's get going. one more tardy and you'll have to spent Saturday in detention inside of crawling around in the living room making presents for me." Daddy said and lead the way out the door.
Katsuki who loved being a little present maker, gave no argument.

Getting to school with a few minutes to spare, Kirishima and Katsuki split up, their lockers where on different floors and the blond noticed something weird as he walked towards his locker.
Normally the other students steered clear of him or gave him looks of hate because of his bullying ways, which was how he liked it.
It was part of his (in his mind) brilliant cover for his big baby life with daddy, that in public he was the meanest toughest asshole you ever had to deal with. Daddy wasn't so fond of the plan but Katsuki could endure any of daddies punishments and truth be told, while daddies spankings hurt and Katsuki didn't get off on them..well, they helped him feel like the little boy he really was.
Still today as he walked to his locker he was getting lots of chuckles and smiles. 
a couple of girls were whispering to each other and pointing at him, then both burst out laughing and he raised a eyebrow.
he stopped to go and ask them what was so funny when a boy from a grade lower then him came over, wagging his eyebrows for the sake of the crowd and then spoke up.
"Are you lost little guy? Do you need me to help you find your daddy?" 
"..The fuck did you say?" Katsuki asked, going to go for a badass pose when anther student from behind swatted his thigh.
"Bad boy! no potty mouth!"
Katsuki yelped and jumped at the swat, more from shock then pain but the reaction got a chuckle from everyone. turning around to slug whoever had slapped him, the slapper had blended into the crowd.
"Alright, who's got the balls!?!" Katsuki growled, and started to take a battle stance.
"Awww somebodies all grumpy!" a voice from the crowd called.
"I think he needs hims paci!" anther called.
Katsuki's mind was racing now, his cheeks turning red. 
'what the FUCK is going on here?!?' he thought. 
The stand off came to a end when the warning bell rang.
"Aww, better hurry up and stock up your diaper bag little guy!" was the second to final insult hurled Katsuki's way though as the crowd moved, SOMEONE patted his ass!
"he's still clean!" came the final insult and Katsuki was left sputtering in rage, before stomping off to his locker.
almost ripping the door off it's hinge, he found a pastel blue pacifier on a whine cord hanging inside of his locker, with a note taped to it.
'Suck on this before you end up crapping yourself' the note mocked, and he didn't know the handwriting.
'..Somebodies gonna die toward.' he growled red faced, and yanked the paci down and tossed it in a nearby trash can.
packing his books into his school bag he dashed for class.

if he'd of thought the classroom would be a sanctuary from his torment, he'd been wrong as right there on the chalkboard for home room was a drawing of him, in just a diaper and a baby bonnet squatting and who'd ever done the art had added stink lines.
with his distinctive hair it was clear just looking who it was suppose to be, but if there had been any doubt it's been labeled in big bold letters "BABY KATSUKI BAKUGO GOING BOOM BOOM!!"
Katsuki let out a soundless screen and almost blasted the chalkboard, but restrained himself, barely and erased the drawing and turned to face the smirking faces of the the rest of the class.
"OK, which one of you twat monkeys has a god damn death wish?" he growled.
"Sheesh, somebodies a grumpy baby." Tenya chuckled, adjusting his glasses.
"Maybe he needs a diapie change already." Yuuga suggested and laughed.
"No, i think we'd all KNOW if the baby was poopie." Momo giggled, holding her nose and waving a hand to prove her point.
"G-Guys..Come on.. be nice..it's not his fault if he needs diapers.." Midoriya said, sweat dropping. 
"I DON'T NEED GOD DAMN DIAPERS!" Katsuki yelled.
"oh wow, then that makes it worse! you wear'em by choice!" Jirou chuckled.
there was throbbing vein on Katsuki's forehead and he was about to blow up the whole classroom when not only their teacher came in, But Kirishima.
"everyone, calm down and take your seats please."
Fuming and blinded with raged, Katsuki stumbled for his desk and got some d'aww's and 'baby can't walk yet' comments from the class.

the rest of the morning crawled by, with Katsuki receiving more then one note with various drawing of him being a big baby, or worse questions about how his diaper was holding up.
so was it any wonder that his school work for the day suffered as a result, and when he was asked to read out loud for the class he stumbled over even the most basic of words, which got quiet chuckles.
Come lunch time he couldn't wait to get away from all of them, and add into it that his belly was growling from not only missing supper last night but breakfast this morning.
the tummy growls had gotten him even more teasing but he didn't even wanna think about that right now.
Kirishima had been called away just before lunch break and so Katsuki didn't have his daddy to help him calm down as he strolled into the cafeteria. he went and picked up a lunch tray and scanned the crowd for Daddy's trademark red hair but then first noticed a crowd at the back of the cafeteria and then noticed WHAT they were all looking at.
there, in blown up giant posters were 6 pictures of Katsuki in all his baby glory. 
The first picture had him triple diapered and asleep, sucking on his thumb on a blanket on the floor. he was face down and ass up and using a teddy bear as a pillow. 
He didn't recognize when the picture had been taken but daddy HAD told him he'd end up like that more often then not when he conked out on the floor.
The second picture had him laying on his back, hands balled up in fists and rubbing his eyes and laying on a teddy bear print changing mat, and in a clearly loaded diaper. 
THIS one he reorganized as the first time he'd loaded a diaper for daddy, he'd only meant to let out a little bit to try but his butt hadn't listened to him. he'd been hysterical for a hour but daddy had given him LOTS of hugs.
Picture number three had him asleep again, this time in a crib and wearing a teddy bear onesie with a bear eared hoodie to go with it and a fluffy tail.  he was also hugging a teddy bear to his chest and drooling up a storm.
That had to of been from his birthday, because that was what daddy had gotten him and he'd tried to wear it as often as he could.
Picture number four he remembered taking not that long ago, and had assumed that Daddy had been joking about sharing it, but it was becoming PAINFULLY clear who had posted all of these. 
It had Katsuki in a thick balloon print diaper sitting on a duck shaped training potty, holding onto the handles and filling his diaper, a look of pure pleasure on his face even though he was blushing.
Moving onto number five and Katsuki felt himself pale even though he was blushing, making for a interesting look. it showed him on top of a teddy bear that was a foot taller then him, hugging it around the neck and kissing it, and from the blur around his pampered hips it was clear to everyone what he'd been doing. he couldn't even pin down WHEN this had been, as it was the only way he'd been allowed to get his rocks off.
the last picture had Katsuki again in just a diaper, but he had paint all over himself and was holding up a poorly made finger painting for whoever was taking the picture to see. of course it was Kirishima but that much wasn't in the picture, though the painting was signed 'To daddy love Baby Katsuki'
Katsuki felt his knees going weak and he tried to say something, anything as countless students laughter, chuckled and took pictures, then someone noticed he was there.
"HEY EVERYONE, THE BABIES HERE!"
practically the whole school turned and started laughing at Katsuki, and the taunts and jeers came.
"What a big dumb baby!"
"Stuffie humper!"
"Diaper pooper!"
"who's the big baby now?"
"i bet he's filing his diapers now!"
"Cry baby cry baby!"
"Diaper boy! Diaper boy!"
it was that last chant that caught on and Katsuki whimpered and whined.
"SHUT UP! SHUT UP ALL OF YOU! I'M NOT WEARING A DIAPER! I'M NOT! I'M IN UNDIES! T-THOSE WERE ALL PHOTO SHOPPED! STOP LAUGHING AT ME!" he screamed, stomping a foot and his voice cracking and going higher and higher pitch. 
"prove it!" Called the geek he'd beaten up yesterday.
"yeah! prove it!" a girl he'd tormented last week agreed.
"H-How can I prove it?!?" Katsuki huffed, and whined, fighting back tears. Where was daddy!?! he needed daddy!
"Drop your pants!"
"yeah! drop your pants and show off your undies!"
"drop your pants! drop your pants!"
It was a mob action mindset at it's worse, and Katsuki knew it would only get worse if he didn't give the crowd what they wanted. thankfully for him, it was a undies day and he just prayed that daddy had picked a basic white pair of briefs for him when he'd been dressing him this morning.
of course if Katsuki had been thinking clearly, he would of realized that since daddy had set this all up, there was no way in hell this would of ended well. 
but can anyone really blame him for not thinking of that?
Undoing his belt to a cheer from the crowd he undid the button on his pants and let them drop to his ankles, smirking. 
"There see? I'm in big boy underwear!" he said, not bothering to look down.
the crowd exploded in laughter and he furrowed his eyebrows in confusion, then the geek from yesterday called out.
"Nice pull ups! I guess compared to the DIAPERS those ARE big boy undies for you!"
Katsuki's eyes went wide as saucers and he looked down to confirm that not only was he indeed in a pull up, it was a barney one.
"I-I no! I..But..Daddy dressed me..and.." Katsuki whimpered and cried.
"Bwhahahaha! he doesn't even dress himself! he really IS a baby!"
"what a dork!"
"What a baby!"
"WHAT A LOSER!"
more laughs and taunts and Katsuki couldn't take it and started to bawl, even as the front of his pull up started to swell and Barney's smiling face faded away.
he was wetting himself.
He couldn't take it anymore and turned to run away, but forgot about how his pants were around his ankles and tripped, landing face down and ass up and giving everyone a perfect view of what happened next.
maybe it was all the teasing, maybe it was all of his nerves. maybe it was from the laxative powder that Kirishima had slipped onto his paci for a bit this morning before he woke up. 
In any case he found himself stuck there as his body suddenly had a payload to get rid of and he let out a massive fart that shut the crowd up for a second. but only a second.
"wait..is he going to.."
"No way!"
"ah jeez, if his FARTS stink this bad.."
three loud and powerful farts came out in a row and then the back of Katsuki's pull up started to puff out as he cried and sobbing, pounding a fist on the ground and putting his forehead to the floor. whether his cries and sob and behavior was from the shame of what he was doing or just trying to force what looked like a painfully large movement out was anyone's guess, though most believed it was the latter.
the puffing of the back turned into a large lump that was poking out the back of the pull up and one boy who's quirk was force fields thought quick as it looked like the big baby was gonna leak.
Forming one around the pull up the lump shushed against it and then as Katsuki screamed out "DADDY!" the mess was smushed all around. 
the ONE thing the force field couldn't contain however was the smell and lots f students started to hold their noses even as thy laughed and waved hands.
"YUCK! what did you eat? roadkill skunk?"
"Somebody open a window!"
"Are we sure THIS isn't his quirk? super stenches?"
with his poopies all out and it all over, Katsuki was crying big time and blubbering for daddy.
"Awww, did somebody have a accident?" Came Kirishima's voice.
Though tear filled eyes Katsuki looked up and saw daddy, who had a large diaper bag with him.
"You..you.." Katsuki whined and whimpered.
"am here to save the day." Daddy said, then held his nose. "whew, just in time, force field or no force field, i don't think that load is staying contained for long!"
Daddy came over and scooped the blubbering baby up, and Katsuki sniffled and buried his face into daddies chest, getting a d'awww from the crowd.
'it's over..d-daddies gonna take me away and get me changed and-' Katsuki thought, eyes closed.
then he felt himself being plopped onto a changing mat that had been set up on one of the lunch tables.
"D-Daddy?" Katsuki asked, opening his eyes. no way he was gonna change him HERE..in front of everyone!
"Shh, be a good boy and let daddy change your stinky bottom." Daddy said and winked.
this was a humiliation a step too far, even in light of all of this and Katsuki screamed and thrashed about, shaking his head no and yelling it it too, till daddy rolled him on his tummy and got the kid making the force field to drop it, then walloped his squishy backside.
"Little man! that is enough! you are going to be a good little boy and let me change you're pull up and put you in a nice thick diaper, then you're going for a nap, or daddies gonna paddle your bum and then all of that will happen anyways! got it?"
Katsuki bawled and whined, but nodded he understood.

One change later, and earning a new nick name to go along with all the others he now had (the new one being little nub..go ahead and guess why) and Katsuki was in 4 for his over night diapers and had been changed into a light blue t-shirt with a teddy bear in a night shirt and night cap sleeping on a quarter moon on the front.
He'd been given a ba-ba of formula to drink while he was changed, and it had been oddly filling but didn't make things any better for him as he now had to wave night night to the rest of the school.
scooped up with dadies hands under his butt and his legs sticking out behind daddy while he held onto daddy with his arms for support, Katsuki was carried towards the shop class where they had built a crib just for the impending big baby.
he was sulking and whining and looked eyes with Kirishima as he was carried away.
"..why?" he sniffled.
"because I told you to stop being a bully or else. you didn't wanna listen. now you'll NEVER be a bully again, and will see what it's like to be picked on. I know it's a hard lesson, and trust me, I didn't wanna have to teach it to you like this. Just, you left me NO other choice." Daddy said.
"I-I would of stopped if you'd of told me this was the punishment.." Katsuki pouted and whined.
"...Huh. didn't think of that. oh well, too late now. Look at it this way. you'll get to be a big baby ALL the time now. and don't worry, daddies never gonna let anyone physically hurt you." Kirishima said and kissed the huffy boys cheek.
Somehow, that didn't make things better but Katsuki just didn't have it in himself to fight anymore.
the bully terror of hero academia was gone, replaced with a huffy diapered toddler who could only strike back at his tormentors with stinky diapers. 

The end