Stewie starts going to the gym with Peter after he gets beaten up by Joe's baby daughter Susie, but just when it seems that his hard work is paying off, Peter reveals that he's been giving him anabolic steroid. Meanwhile, Chris begins dating a popular girl at school, only to see her popularity subside.

When Mayor West marries Lois’ sister, Carol, they move into the Griffin’s house to be one big “happy” family. To make room for everyone, Stewie is bumped out of his room and takes over Chris’ room, but not everyone is annoyed by the change. Peter and Mayor West bond and become best friends.