You and Katsuki are in a relationship and he gets pretty jealous over you but he would rather die than actually admit it or show it.

But you were getting oddly close with [whoever you want] and Katsuki was getting jealous about it.

He was walking down the hallways to his dorm as you caught up to him and tapped his shoulder while walking with him, asking him about answers for the homework.

“Why don’t you go ask [name]?” He said bluntly and he didn’t even look at you.