Season 4, Episode 5 | October 21st, 2010
Amy Farrah Fowler tells Sheldon that she wants to introduce him to her mother. Sheldon freaks out, thinking that Amy wants to take their relationship to the next level while he is completely fine with the level they're currently at. He proceeds to go out of his way to avoid her and even takes the address numbers off their building in hopes of confusing and thwarting her. In the end, she gets to him and explains that she simply wants to introduce him to her mother as her boyfriend so her mother will get off her back once and for all. She doesn't want to change a thing about their relationship. Sheldon, intrigued by the ruse they're going to play, happily agrees.
Meanwhile, Leonard is depressed that everyone seems to be paired off except for him. He invokes the girlfriend pact with Wolowitz which requires the girlfriend of one of the guys to set up one of the other guys with her friends. Bernadette brings her friend Joy to a double date with her, Howard and Leonard. Unfortunately, Joy isn't quite who Leonard had in mind and the date ends up being one of his worst.