Watch The Big Bang Theory: Season 4, Episode 21

"The Agreement Dissection"

When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roomate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges due to the agreement's vague wording, much to Sheldon's dismay. When the guys take advantage of Priya's skills in order to eat Greek food on pizza night, Sheldon goes to Penny, who invites him to a girls' night out with Amy and Bernadette, which Sheldon agrees to after Penny mentions that they may be talking trash about Priya. After the girls drink some cocktails, they decide to take Sheldon dancing, which Sheldon reluctantly goes along with. After dancing, Sheldon takes an intoxicated Amy back to her apartment and as well as talking about Priya, meets a monkey who is addicted to smoking cigarettes. Amy tells Sheldon not to give in to Priya's law skills, before kissing him and going to her bathroom to vomit.
The next day, Sheldon writes a more detailed edition of the roomate agreement and asks Leonard to sign it. When Leonard shows his reluctance, Sheldon activates a "self-destruct sequence" on his laptop, detailed in the way of Star Trek's voice command and display, if Leonard doesn't sign the agreement within a minute, it will send an e-mail to Priya's parents informing them of her relationship with him. Leonard believes that Sheldon is bluffing and doesn't see the harm in Priya's parents knowing, but Priya, knowing that her parents are against her dating an American, tells Leonard to sign the document before the timer runs out. Leonard finally agrees and Sheldon aborts the program. Later that day, Sheldon speaks with a hungover Amy via webcam and reprimands her slightly for drinking, but also thanks her for the advice that she gave him the night before, while Leonard argues with Priya about whether or not she's ashamed of him.

Title reference: Priya using her skills as a lawyer to nullify Leonard and Sheldon's roomate agreement.