katsuki is your boyfriend, and you are going over to his parents house for dinner tonight.

you would knock on the front door of your boyfriends house, unsure of who will answer.

the door would open.

mitsuki (katsukis mom): “hey honey ! come in, come in.”

katsukis mom, mitsuki, would soon call out to katsuki:

“BRAT SHE/HE IS HERE.”