Can you help me figure out if I am biual?

I always thought I was straight but I've noticed that whenever I see a big/tall man I cant help but wonder what he is packing. I only ever fantasize about women but at the same time big strong alpha men make me (a small guy at 5'8) feel so feminine. I find myself fantasizing about being "forced" to orally please them and such. Am I ? Any ysis or comments?