needing advice

I unfortunatly like my friend and the worst part is he has a girlfriend. I'm trying to avoid him as much as possible without ruining a great friendship! We don't really see each other much so that makes it easier I have met his girlfriend and the whole time he was just talking to me, texting me and showing off. I feel really bad and I don't know what that means????? Like I said I AM avoiding him but at the same time we are FRIENDS. please know liking him does NOT make me "that girl" "hoe" "slut" or a "home wrecker". I'm just simply asking for advice as I DONT want to ruin a relationship and our friendship.