Not sure if this has been discussed before but... Do you think that there are physical differences between straight men and gay men? The most well known would probably be the finger thing (supposidly if your middle finger is longer than your pointer finger, like a woman, you are more likely to be gay...). However, I personally have noticed some differences on my own body.
For one, I think I have "girl" hips. I say this because, well, they look like girl hips. They kind of bulge out, but they're not love handles (they're not fat, they're bone). Also, after a few weeks of wear, my belts develop a curve, and become crescent shaped. I have asked my straight friends, and this does NOT happen to any of their belts. However, I was in Banana Republic, and all of the womens' belts were the same cresent shape.
Another case of this would be my flexibility. I have always been super flexible, and would always kick ass in the flexibility tests in Phys Ed class. I'm always one of, if not THE, most flexible boy in class, and about as flexible as the average girl. I do not stretch, do yoga, or anything else that might increase my flexibility. It's always been completely natural.
Maybe my situation is just a fluke. Who knows?