Plot[ edit ] As Peter and Lois discuss a family trip to Maine , Chris alerts his parents that he has been suspended indefinitely from school for telling an inappropriate joke to his classmates. Assuring Principal Shepherd it will never happen again, Chris reveals that he learned the joke from Quagmire. Peter asks Quagmire to tell him the joke, which he finds so funny that he involuntarily defecates. Realizing this, Joe and Quagmire play a series of pranks on him, making him soil himself by repeating the punchline to him, which Peter eventually thwarts by wearing Quagmire's pants. Peter asks Quagmire where he heard the dirty joke in the first place, and Quagmire reveals that he heard it from Bruce.