a girl friend who only wants to give you painful hand jobs and tell you about her old boyfriends. ("B.F." for best friend. "Skinner" for a hand job. B.F. Skinner was a famous behavioral psychologist of the 20th century)
My first girl friend was a real B.F. Skinner. All she ever did was yank on my cock and tell me about the guy she lost her virginity to.