Sex with Girlfriend, Fantasies of Men. I've only had sex with my girlfriend of four years, which I think makes me a lesbian, but I also feel attracted to men which I think makes me bisexual, although I've never been with a man sexually. Lately our relationship has been stressful, and male-related fantasies I considered buried are resurfacing. People don't always fall into a strict category of heterosexual, homosexual, or bisexual, but often fall somewhere in between.
Some people define their sexual orientation solely by the gender with which they're sexually active.
Others may also take into account whom they feel attracted to, or whom they choose to fantasize about. Point being, labels can be difficult and restricting. Only you can decide for yourself where you might fit on the continuum of sexual orientation. One important thing to think about, though, is separating your sexual orientation from the problems you're having with your girlfriend. You're best off resolving the difficulties with your girlfriend first, only afterwards sitting down to think long and hard about sexual orientation and what, if anything, you want to do about it.