I don't consider myself bisexual.

I know what you mean. I think it's the same with guys, too.
My theory when it comes to sexuality is this; When you're starving, you'll eat anything. Also; Even vegetarians crave meat. I think it's clear which is suppose to be for females and which is suppose to be for males. XD I don't believe that even a heterosexual or a gay person would never have sex with someone of the same/opposite gender. Sexuality runs a lot deeper than the physical, despite society's definition.