It took everything in you to not burst out from laughter right now. The dumbfounded expression given from Katsuki when you repeated the words "I know what you did" was really a sight to behold.

Well, originally you didn't have anything to do so you decided to mess with your boyfriend about how you knew what he did when he really didn't do anything wrong. But ofcourse you didn't tell him that. So now here you were, with Katsuki sitting on the couches and you standing in the common room, pointing at him accusingly.

"The hell did I do?!"

Katsuki asked in a rather annoyed tone. I mean, it was expected for him to get annoyed but you thought he'd be atleast a little confused. Which he was. He was just really good at hiding his confusion for some reason.