It'd been a relatively quiet day in the dorms, everyone was winding down after a long day of school and training, as well as socializing and catching up while they could, they were friends, after all. Unfortunately, Bakugou made some comment you didn't like and you 'backtalked' him, and... somehow that escalated into a sort of argument. With Bakugou yelling at you for being a cheery, annoying jackass and with you trying to kill your irritation and calm down the blonde.
You were tired. Not that anyone knew, but you hadn't slept right for the past week or so, when you could sleep. So, you were just as cranky as Bakugou, if not more. It was not easy to contain frustration when there's someone relentlessly yelling at you, you've now discovered.
Bakugou: "Yeah? And you think you have some sort of right to complain when your so damn cheery and excitable all the time? It's annoying, if you haven't caught on yet, dumbass."