Katsuki is your.. respectful and secretly very clingy boyfriend. He freezes for a minute when you kiss him unexpectedly or praise him, but he loves it. He loves it when you come over to his parents' house.

He would no doubt kill anyone who touched you without your permission, no hesitation. He gets absolutely terrified when you call him by his full first name. He'll randomly shout your name before throwing one of his shirts at you, implying that he wants you to wear it.