Sheldon: More to the point, it's about finding a way to keep Leonard and Stephanie together.
Howard: Oh, I don't think you can.
Sheldon: Well, why not?
Howard: Look at Leonard's record. 27 days with Joyce Kim.
Raj: During which she defected to North Korea.
Howard: Two booty calls with Leslie Winkle.
Raj: For which she awarded him the nickname "speed of light Leonard."
Howard: And a three hour dinner with Penny.
Raj: Which would have been two and a half if they ordered the souffle when they sat down.
Howard: Based on the geometric progression, his relationship with Stephanie should have ended after 20 minutes.

Howard: You know, I'm really glad you decided to learn Mandarin.
Sheldon: Why?
Howard: Once you're fluent, you'll have a billion more people to annoy instead of me.

Howard: I invented a game. Want to play?
Leonard: Sure.
Howard: It's called Emily or Cinnamon. I give you actual quotes I've heard Raj say, and you guess if he was talking to his girlfriend or his dog.

Bernadette: Does your mother call you every day at work to see if you had a healthy lunch?
Howard: My mother calls me every day at work to see if I had a healthy bowel movement.

Sheldon: *knock knock knock* Leonard? *knock knock knock* Leonard? *knock knock knock* Leonard?
Leonard: What, Sheldon!? What, Sheldon!? What, Sheldon!?
Sheldon: Tell me what you see here.
Leonard: The blunt instrument that will be the focus of my murder trial?

Sheldon: I would ask you to find some way to suppress your libido.
Penny: I could think about you.
Sheldon: Whatever works.

Sheldon: Well, this is very pleasant.
Leonard: I'm glad you're enjoying yourself.
Sheldon: And you said there would never be enough pasta for the three of us.