Labeling can get a bit out of hand. Especially with the whole top vs bottom (or "versatile" dilemma; I've been asked by friends or acquaintance all of the time, which one I am. This is even common amongst gay circles.
I just want to say, do I ask you explicit details about your sex life? It's just assumed that the man is the top and the woman is the bottom in the relationship, it's easier for many people to help explain behavior they have little knowledge of more concretely and in terms that they understand better such as the sex dichotomy of heterosexuality. Though in some relationships, there is a clear dichotomy of dominance, a lot of the time there is not.