Katsuki was your boyfriend and wasn't the perfect one. He could yell and curse most of the times even at you but he had his limits obviously.

It was morning before class and you were waiting for the others and the teacher with him. He noticed that you messed up your tie.

Katsuki: How can't you be able to tie this correctly huh? Can't do simple things.

He grabbed your tie, folding it correctly.