The Big Bang Theory Season 3 Episode 19
The Wheaton Recurrence
The episode opens with Penny and Leonard in bed and after quoting Penny quotes Star Wars, Leonard confesses his love to her only to get a thank you back. Despite their problems, the not-so-happy couple joins the rest of the gang in a bowling match off against Stuart's crew, which includes Wil Wheaton as a substitute. During the first round, Leonard harasses Penny about not saying I love you back and she eventually storms off. Sheldon manages to get them a do-over, but this time, Wheaton gets inside Penny's head and convinces her to break up with Leonard. She ends up breaking up with him, storming off. The boys end up losing and forced to wear female superhero costumes.