Since I joined in 2009, I've considered myself bi because at that time, I was having sex with girls more than with guys. And it wasn't so I could hold on to something or say part of me was straight. I couldn't care less of what people think of me, I used to care, but not anymore. I genuinely enjoyed sex with women.
But that's all. Just sex.
I didn't want to commit to a relationship because the only relationships I've had (4) all ended in jealousy on their part or their constant wanting to know where I was at, trying to figure out if I was cheating on them with another girl. But I was cheating, just not with another girl.
In 2010, I posted here about a very serious issue involving 2 straight guys. It all ended well (thanks to the advice of posters and the realization from my part) and one which resulted in my first gay relationship with a man. That relationship ended the beginning of December 2010. It was my decision to end it, but that's a whole 'nother issue. You can look for the thread, but frankly it's too embarrassing.
2011 was a big turning point. I started to go out more, experienced my first gay club, the whole scene. As time went on, I've had less and less sex with girls. Now here we are. The last time I've had sex with a girl was December 21st, 2011. I remember because it was the day of one of my close friend's party and we had sex that night.
I don't think it's fair for some people to label me as bisexual if I haven't had anything intimate with a girl for over a year. Yeah I find women attractive and sexy, but who doesn't?
So I guess that's it, I'm changing the orientation now.