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

Leonard: What am I supposed to do?
Penny: Err, keep your mouth off other women.

Leonard: If I take it off, Sheldon wins.
Penny: Sweetie, every night you don't kill him in his sleep, he wins.

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.

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.

Stephanie: Where did you get the stethoscope and the blood pressure cuff?
Sheldon: My aunt Marion gave them to me for my 12th birthday. She thought if I failed at theoretical physics that I should have a trade to fall back on.