Not everyone is a Buttman, since not everyone is a man (Buttwoman), and some are more "Boobmen". I personally am a Buttman, since you can have a nice ass without big boobs, but having a big boob without a nice ass is just awkward.
I mean, when I imagine it, it just seems physically impossible, the center of gravity will be beyond the support base and the poor woman will just fall forward.









