Any one seen Fight Club? There's a fight scene involving a guy who has bitch tits.
Bitch tits form when a male heavily abuses steroids. Given that all men have a small amount of oestrogen in addition to
testosterone, steroids greatly increase the level of
testosterone in a man's body.
However, in an attempt to keep
testosterone and oestrogen at steady levels in relation to each other, the body produces much more oestorgen than necessary, resulting in feminine characteristics, namely breasts.