He keeps telling his friends...im confused...?

There is a guy that has liked me for a long time (all school year and last summer, but he still dated girls since he felt i was too young and my dad). I liked him...still do, and he knew i had liked him a few months ago when he found out, but he claims right now to like another girl.. i know her. Although, he keeps telling his friends how they have to impress my dad, theyll never have me, i wont like them, and tells them about things we do together.. basically making them back off and chicken out of any relationship with me. He also puts down any guy i mention... normally. I dont understand why he does this if he likes her. Aside from this though he says im really really pretty but too young (im an incoming sophmore, and he is an upcoming senior). im just confused sorry...