I guess you could say I'm Bi because I'll have sex with men and enjoy it. It's not all cut and dried as I don't really desire to be in a relationship with a man and I don't really fancy men as such (as in if I walk down the street I'll see women I think are hot but I never think anything about any men at all, or any celebrity men either) so define that how you will!
For years I assumed I was straight, never thought about men in that way at all. Late teens a couple of gay & bi blokes came on to me and offered me sex more than once...even offered to blow me with me needing to do nothing else but I politely declined. At some point after that I must have gotten around to thinking about it as I recall just being interested in the gay porn section of the adult dvd brochures I kept getting sent. Something must have got my attention because I plucked up the courage to order a gay dvd on the quiet, hid it when I got it and I tell you, I wanked to that thing big time.
It then took me years of thinking about whether I'd like to try anything myself (whilst still having relationships with women as normal and fancying women as always) coming close by joining dating sites but then backing out last minute and feeling guilty and ashamed before I finally experimented a couple of years back.
So now basically I still fancy women, I look to get into relationships with women and all that's the same, I love shemales and shemale porn, would gladly get into a relationship with one if I fancied her and we got on well etc etc, but still don't fancy men in that way and could never imagine being in a relationship with a man, yet....I still occasionally crave and enjoy gay sex.
I don't know if that's what it is like for a lot of curious/bi guys or not but that's it for me. I'm still into women more than anything but I like cock and a great ass on a guy and it doesn't bother me at all, it's just sex as far as I'm concerned. I just wish society was much more open to it than it obviously is. If society were much better generally then you wouldn't have so many people (especially teens and young people) going through sheer hell with their sexuality and shameful feelings.