What does it mean when a girl smiles at you at eye contact and has a bf?

that she is insecure about her boyfriend and that she maybe wants to date someone else. but if she just does it to flirt with you she a slutty,bitchy hore. sorry but i mean you have one guy but go for more. no way. so if she just wants to break up with her current bf give her time or someting or it could be that your overreacting and it was just a friend moment. like a one on one eye contact moment. READ I SAID FRIEND! and you misread it. either way try to pick a girl that doesn't cheat on you or likes to change flavors. cause if she changes flavors shell change you