It took them ages, mostly because they had to be quiet as hell and Katsuki was being a little bitch about being caught, but eventually it was done.

"Fuckin' finally won't have to keep getting in trouble because of your dumbass," Katsuki huffs, but he looks pleased.

Still, Eijiro rolls his eyes. "Oh shut up! I wouldn't keep getting caught if you didn't go to bed earlier than my grandma! Not my fault Aizawa knows when to start keeping watch! Besides he wouldn't have ever known if YOU didn't get caught first!"

Katsuki hates that he's right.

"Whatever," he grumbles, shouldering Eijiro out of the way to inspect the hole they created inbetween their two rooms, big enough for even Eijiro's giant ass to pass through.

It's a good hole and Katsuki's kinda proud of it, even if he is moderately terrified of getting caught

But when weeks go by and Katsuki and Eijiro are able to slip into each other's room at night easily and without detection, Katsuki finally breathes a little easier, his attitude even cockier at getting away with destruction of school property.

He's officially a bad boy, Eijiro says, which Katsuki loves.

Even more time passes, and Katsuki and Eijiro decide to get even bolder. It takes time, but eventually the hole is even larger. It's big enough to slide in Eijiro's mattress and the pieces of his dismantled bed frame.

For months they live like that, Katsuki room designated as their bedroom with Eijiro's bed shoved up next to his, and Eijiro's room their living/study area.

"It's like when we have our own place," Eijiro says.

Katsuki likes that even more than being called a bad boy.

It's only when the school year is up that they realize they maybe might have fucked up a little, when Aizawa is standing in Katsuki's room for the final dorm inspection, eyes wider than either boy had ever seen, staring at the now literal archway they created.

"I thought you broke up," he finally says, eyes not leaving their creation. "You stopped sneaking into each others room..."He doesn't finish his sentence, just keeps staring with disbelief.

"We're sorry," Eijiro says.

"I'm not," Katsuki's smirks, he's a bad boy now after all.

Finally Aizawa sighs. "You two are lucky as hell we've got a teacher with a literal cement quirk on campus."

But he doesn't seem all that mad, or maybe it's because it's summer & he's just too tired to care or it's a graduation present but he doesn't tell their parents either.

When Eijiro and Katsuki get their own real place, a tiny one bedroom in-between both of their agencies, Aizawa is the first to send them a house warming gift. A small fern and a tub of spackle with a card that reads, "just in case."