I think it only matters how you see yourself. I find woman attractive physically, and once in a while find myself in a sexual situation with a woman. I don't pursue women for sex, and when it happens, it's just a matter of circumstance. Sometimes I turn it down, sometimes I don't. I watch straight porn, but only because the guy is hot. I consider myself gay because I'm physically and emotionally attracted to men. I desire and pursue men sexually. Forgetting that I've been with the same man for over 4 years, and we bought a house together, my family considers me bisexual simply because I've had sex with women over the years. They have even argued the point with me telling me that I'm wrong when I tell them I'm gay. Personally, I think the bisexual label makes it easier for their tiny little minds to deal with. I know who I am, and the label they choose to put on me doesn't matter.
