S5, E11: When a bully harasses Chris, Peter goes to his defence but ends up beating him up. Peter realises bullying is fun and begins to bully everyone in the house. Finally, Chris stands up to Peter and beats him senseless. Meanwhile, Stewie goes out without sunscreen and becomes obsessed with getting a tan. After Brian leaves him in the tanning booth for six hours, Stewie gets sunburned and fears he has cancer.