Penny: I mean, what have women said to you when they wanted to slow a relationship down?
Leonard: I really like you, but I want to see how things go with Mark?
Penny: Yeah, that'll slow it down.

Sheldon: Woman, you are playing with forces beyond your ken.
Penny: Yeah, well your Ken can kiss my Barbie.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Penny: I mean, who even reads Scientific American?
Leonard: It's kind of a big deal.
Penny: If it's such a big deal, how come the biggest celebrity they could get for the cover is a molecule?

Stephanie: I don't see anything at all, Sheldon.
Sheldon: Well, you're the doctor, but I am constantly hearing this annoying sound.
Leonard: Me too.
Sheldon: Is it a high frequency whistle?
Leonard: No, it's more of a relentless, narcissistic drone.

Leonard: Don't you think if a woman was living with me I'd be the first one to know about it?
Penny: Oh, sweetie, you'd be the last one to know about it.

Sheldon: I trust Leonard satisfied you sexually last night.
Leonard: Oh good God! Sheldon we don't ask questions like that!
Sheldon: I heard you ask it over and over. How is it inappropriate for me to ask it once?
Stephanie: He did very nicely.
Sheldon: See? She's not offended. And now you finally have an answer.