The Desperation Emanation (2010)

When Amy Farrah Fowler asks Sheldon to meet her mother, he starts to get worried, as Leonard tells him that meeting Amy's mother would mean she is his girlfriend (which he denied up to that point by referring to Amy as a "girl" and a "friend"). He freaks out and tries to "break up" with her. When she tells him it is only to please her mother, and that she doesn't actually want to be his girlfriend, Sheldon is relieved. He goes along with her idea and tells Amy's mother via webcam that he is having regular intercourse with her daughter, which freaks her out just like Amy wanted it to. Sheldon then asks Amy if they actually should have sex, before adding "Bazinga!".

Meanwhile, Leonard has his own problems. Frustrated by the fact that Howard has Bernadette, Sheldon has Amy, Stuart has a woman he met at Comic-Con, and Raj claims to have a girlfriend who is deaf , Leonard invokes the "Girlfriend Pact" with Howard, last mentioned in The Creepy Candy Coating Corollary from Season 3. Howard gets Bernadette to set Leonard up on a date with one of her friends, a woman named Joy who is into fitness and martial arts. This date ends up being one of the worst in his life. However, Leonard agrees to another date with Joy because he may get to have sex with her.

Recurring characters: Mayim Bialik as Amy Farrah Fowler and Kevin Sussman as Stuart.

Note: Kaley Cuoco is absent from this episode due to a broken leg sustained during a real life horseback riding accident. This is the first time that a regular cast member has not appeared in an episode. During the episode, it's mentioned that the street address of Sheldon's and Leonard's apartment building is 2311 Los Robles. Also, this episode airs Chuck Lorre's 300th vanity card.

Title reference: Leonard's desperation in wanting a girlfriend.