"THE FUCK YOU WE'RE THINKING?!" Katsuki shouted, then slamming a rolled up magazine on your head. "So being an idiot is your entire persona or what?! You know better than that!"

Bakugou knew you were always doing something trouble some without his presence. Unintentionally, he became your "babysitter" to look after so your "dumbass won't do anything stupid with him."