Season 5: Episode 88: The Tan Aquatic with Steve Zissou
When a bully harasses Chris, Peter goes to his defense, but ends up beating him up. Peter realizes 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. While waiting for the results of his cancer screening, Stewie begins to live his life as if he had only days to live and drives Brian crazy with his demands.