Sheldon & Penny: 01x08 The Grasshopper Experiment
Penny: Sheldon, what are you gonna have?
Sheldon: I’ll have a Diet Coke.
Penny: Okay, 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.
Penny: So Coke.
Sheldon: Yes. And would you make it diet?