It's a good point, but in the end, I don't think it's anything about masculinity or femininity, but the true sex behind it.
Although, really masculine guys aren't that attractive to me. The huge muscles, forests of body hair, deep deep voice... It's completely unattractive. I've been attracted to both sides of the fence, but I find myself being attracted to someone right in the middle, slightly biased towards being feminine (a twink, if you will), but without the annoying personality. Now, if they honestly look like a girl, that's another story.
That's a possibility. I think there's more to it, though. I've never found myself sexually attracted to a girl, even ones I had a real emotional connection with. This, all before I officially come to terms with myself being gay. I tried, too. I was hellbent on forcing myself to be attracted to girls. It just never worked though.
On the topic of this thread, I had a few girlfriends back in day. I'm sure a few of you who regularly attended the old, old chatroom we had might remember the ventures I had with Bekah. She, I was with at the height of my sexual confusion. It was cold of me to do this, but I honestly only started dating her in my attempt to "turn straight". I had this thought that if I had another girlfriend (my last one occurred before my confusion), it would make my problems go away. I basically thought I was having "gay" feelings because I didn't have a girlfriend. Again, massive failure. It didn't work.
I've never done anything more than a slight peck on the lips with a girl. I'm glad.