well seems like you have a problem I'm kinda of in the same sort of situation myself. if the guy really likes the girl and they are committed don't try it it just is going to end up in pain for you its not worth it. if the guy shows interest in you try to show nonverbal signs that you like him to casual flirting and gently touching his arm during conversation helps but don't sound needy or clingy if he says something you don't like hit him PLAYFULLY hit him hard and he'll think of you as just one of the guys. but girl if he likes you go for it!!!