i've known this guy for a while, and he's probably my best guy friend. i liked him when i first met him but i found out he had a gf and moved on. recently, my friends have been setting me up on a couple blind dates and we were talking about it in class and i guess he over heard and started asking like "who?" "when?" and got really quiet/upset and left. my question is, why do you think he gets quiet when i bring up other guys? he has a girl friend, so i don't see why he should stress over or care enough to get upset and leave?