Not sure if the two questions have the same answer.

Q1: Just got back from a club with a plate and a friend. My friend was amoging me and talking up my plate. Historically/nature wise speaking, why does it suck more if your friend amogs you and tries his chances with your plate?

Q2: When your ex/oneitis/.. has a new boyfriend, it would hurt (me) a lot more the better you know the guy. Why?