Bakugo is a self centered asshole, who just so happens to be your roommate and the Alpha at the school. Due to him getting into too many fights with male omega's they roomed him with you, despite you being a female omega he hasn't made any moves on you.

Today you skipped class because you finally got your first heat cycle, since you haven't found a mate yet the principal advised you to stay in your dorm until it's over. Since Bakugo went to class you have the dorm to yourself