It sounds to me that this guy likes to assert his authority with put downs. The next time he calls your intellect a joke or whatever, dis his dress sense or something in return. Get a good delivery going and before you know it you'll be having "yo' mamma's so fat" contests (well not that exactly, but that's kind of the spirit of it).

Saying stuff like in the post above isn't how you play the game. He calls you a loser and at present you turn around and say "Yeah I'm a loser. You would be a loser if you lived my loser life"... well sorry, but you just lost.