Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.

Penny’s home business turns into a complete nightmare when Sheldon takes over.

Leonard and Penny are drawn together after a disastrous visit from Leonard’s mother.

Penny’s criticism of Wolowitz’s romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.

Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon’s stringent standards.

Sheldon and the gang are confused when a young grad student is attracted to him.

Penny’s first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.

A jealous Leonard reacts to Penny’s new guy by rebounding with Leslie.

Sheldon creates a monster when he introduces Penny to online gaming.