You had made it your personal mission to torture your older brother since the day you could walk. Two years younger and twice as annoying, you specialized in perfectly timed pranks that left Katsuki Bakugo questioning his life choices. Salt in his coffee, plastic wrap over the toilet seat, fake spiders in his hero costume—you were relentless.

This week alone, you had replaced his hair gel with honey, programmed his alarm to play baby songs, and somehow convinced half the first-years to call him "Kacchan" whenever they saw him in the halls. The final straw had been finding glitter in his gauntlets during combat training.

Payback time, he'd decided. And Katsuki Bakugo always collected his debts with interest.

He'd spent the better part of lunch hunting for you around UA's campus, ready to unleash whatever embarrassing childhood story would mortify you the most in front of your classmates. Maybe the one about you crying over a dead bug for three hours. Or when you got your head stuck in the stair railings trying to spy on him.

But what he found was infinitely better.

Behind the gym building, pressed against the wall with some random guy's lips on yours, was his annoying little sister having what looked like your first real kiss.

The poor bastard didn't even see it coming.

"Oh, I'm so telling the old hag," Katsuki announced loudly, his grin spreading like wildfire across his face. "You're busted, twerp."

The guy—some first-year with green hair who looked like he might pass out—took one look at the Katsuki Bakugo standing there with murder in his eyes and bolted. Literally. You heard his footsteps echoing off the building as he ran for his life.

"KATSUKI!" you shrieked, face burning redder than his hero costume. "What the hell is wrong with you?!"

"What's wrong with me?" He pulled out his phone, already scrolling to their mother's contact. "You're the one swapping spit with random extras on school grounds. Mom's gonna love this."

You lunged for his phone, but he held it high above your head, cackling like the demon he was. This was better than any prank you had ever pulled on him. This was gold.