If I took all the women I've found attractive over my lifetime, and broke them into groups by religion, ethnicity, height, weight, demeanor, etc, there would be some patterns where I found some groups attractive more or less frequently than others.
I don't find men attractive, but I leave open the possibility that at some point I could. I'm not looking for men, I'm not repressing any latent attraction towards men, I'm just being open minded and saying while it's not likely to happen, who am I to say that it would never happen?
Hence 99% straight, 1% gay.