Bakugou
You were almost too afraid to do it. Keyword being almost. But you were so sick of him always falling asleep on you when you were trying to spend time with him. You’d been sympathetic the first few times, but by the millionth time, you’d just started to get angry. It wasn’t like he gave you more than a few hours at a time, between class and his obsessive training, and the least he could do was have the decency to stay awake during it.
The fact he didn’t even budge when you were doodling all over him was proof enough he was overdoing things lately. Lucky for you, he only woke up long enough to give you a delirious hug goodbye before taking off for his own room; you were pretty sure it was Izuku that caused the resounding thump and series of shouts that occurred not far down the hallway, and definitely not the fact you’d written “asshole” across his forehead. It wasn’t even a lie.
Dabi
It was, initially, Togas awful idea, and when he woke up and saw the mess you’d made of his face, well, she was obviously going to be blamed. Really, you deserved to retaliate when all he did was spend way too much time away from you. Even an evening alone together was almost impossible to get from him, and you’d be damned if you didn’t take this opportunity to really be petty over it. Unfortunately, his scars made black ink almost invisible, so you decided to mix it up and draw all over him in red. It would stand out more.
When he blearily woke up from his place on your couch and gave you a one-armed hug goodbye — that bastard — and wandered off, you smirked smugly. It wasn’t until Toga sent you a candid pic of him and Shigaraki bickering, with the red ink still covering his face, that you actually started to feel a bit anxious. You hadn’t expected him to go straight to the bar! He was supposed to go home and see it! Needless to say, you ignored his phone calls all night, and woke up to five voicemails. The first two were him yelling, the second two were him apologizing but explaining he was still furious, and the last one was him begrudgingly admitting it was funny.
Kirishima
You’d have thought he would be more concerned with the fact he was surrounded by snickering as he passed people in the hallway. But nope. In fact, it wasn’t until he’d made it all the way back to his own room that he’d thought something was up. After all, you tended to hate it when he fell asleep while you were supposed to be studying together; you took all things related to school very, very seriously.
But when he’d woken up, sheepishly apologizing for falling asleep again, you looked perfectly happy that he was finally awake. You’d even helped him finish up his homework before you sent him on his way, when normally you would have told him to get lost and find someone else to do it for him. He really should have known better; needless to say, he didn’t make that mistake again. You’d written in black, thick-lined permanent marker, and it had taken days for it to completely wash away; walking around with half-there dicks on his face was probably the most humiliating form of punishment he’d ever been through. Probably.
Todoroki
It had started out as an accident. A stray flick of your wrist when you’d been drawing near his head, and there it was. The incriminating evidence you’d just drawn on him. Of course, the proper thing for you to do was try to at least make it an appealing drawing, and not just a random black mark across his cheek. He’d left your room with a masterpiece on his face, and you’d honestly been too embarrassed to tell him you’d done it in the first place to stop him.
At some point you’d realized he was going to be bewildered by it; the idea of explaining that obviously your brain had short-circuited when you came up with the idea to fix it would be met with one of his “you’ve got to be an idiot” stares, and you couldn’t bring yourself to suffer through it. Unfortunately, when Izuku commented, however gently and well-meaning, on it in the hallway, he’d promptly spun on his heel and returned to your room, and you’d had to suffer through his accusing stare anyway while you wiped it off his face.
Added Dabi!