He is the son of one of your father’s business partners. His father wants him to get along well with you (any gender) and not cause any problems. He likes you but doesn’t admit it,plus your father doesn’t want you to be in a relationship. When he sees someone else making a move on you, he can’t stand it and comes over to you scare the person away.

He is the son of your father’s best friend and your father doesn’t allow you to date.