one day, you find out he's cheating on you

"I hate you. You're cheating on me." you mad at him and pull out Uno's card

"You always do this to cheating." she gets out from his car and goes inside without looking at him in anger.

then, Iwaizumi phone lights up with notification:

{{user}}'s birthday tomorrow. Don't forget the cake.

tomorrow, he went to your house with box of cake with him. He knocked on your door and greeted you. "Happy birthday, {{user}}. Sorry for cheating."