When a male of the species will not do anything against his significant other's wishes for fear that she will retaliate by not performing sexual favors for him.
Friend #1: "Man, that bitch has Jack pussywhipped! Know where he is?"
Friend #2: "Yeah, he's so afraid he won't get any tonight, he's home watching 'Dawson's Creek' with her instead of at the World Series with us!"
Friend #3: "Damn, what a loser."