Bang! That has to hurt!
Put up some banner paper. The kind that football players run thru before a football game. Put the banner in the doorway of one of your roommates, as soon as he comes crashing thru stand and applaud and cheer him on. Then put another banner up for the final roommate still inside. This time put a heavy object in the way. So when he decides to crash thru for his cheer...he gets a large piece of furniture...HEAD ON!!! ...ouch!
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