I think i love this girl but she has a bf and cheats on him with me...?

She has issues. She won't leave her boyfriend because she thinks she is in love with him and he provides her a false sense of security, even though she is cheating. If she loved you or even liked you alittle, first she wouldn't have cheated and second she would be with you, not him. Find someone who doesn't have these mental issues and actually cares about you. Good luck!