A loud scream from the bathroom

This guy is sitting in a bar drunk. He asks the bartender, "Where's the bathroom at?" The bartender says, "Go down the hall and make a right." Well, all of a sudden, everybody at the bar hears this loud scream coming from the bathroom, and they wonder about what's going on in there. A few minutes go by, and again, everybody at the bar hears another loud scream that came out of the bathroom. This time, the bartender decides to investigate, and he goes into the bathroom to see what the drunk is screaming about. He opens the door and asks the drunk, "What's all the screaming about in here? You are scaring all my customers away." The drunk whines, "I'm sitting on the toilet and every time I go to flush it, something comes up and squeezes the heck out of my gonads!" With that, the bartender looks in and says, "No wonder! You're sitting on a mop bucket, you idiot!!"