We never thought we'd see the day when Sheldon and Raj go to a University mixer together and meet some ladies, Martha (Jen Drohan) and Abby (Danica McKellar).
Sheldon: I'll have a diet Coke. Penny: Can you please order a cocktail? I need to practice mixing drinks. Sheldon: Fine... I'll have a virgin Cuba Libre. Penny: That's... rum and Coke without the rum. Sheldon: Yes, and would you make it diet?