Sexuality is fluid; it moves on a continuum. Such things can't be pinpointed.

While I've always been physically attracted to both men and women, when it comes to the emotional side of a relationship I tend to prefer to seriously date men. It changes all the time, and is really a case to case thing, but more often I end up in long term relationships with men. The connection I often have with a women is so intense, it often can't be sustained.