Help! There's a Cockroach in My Underpants.

Andy, a chronic practical joker, is with his parents at his Dad's boss' house for dinner. Forewarned about practical jokes and facing a live cockroach in his salad, he is sure his Dad will think he put it there. His extended and hilarious attempt to get rid of the cockroach, ends with Andy stuck in a bathroom window with his bare bottom mooning four slack-jawed adults.