Sheldon: I knew we should've never mentioned us living together in the first place.
Amy: She was gonna find out eventually.
Sheldon: Disagree. We've known about evolution since 1859. She still believes in Noah and his amazing zoo boat.

Penny: Do they know why the pipes burst?
Amy: They didn't say.
Leonard: Buildings that have a combination of copper and galvanized steel are susceptible to pinholes and corrosion caused by the mobility of ions in the water. Can't have your head shoved in a toilet as much as I did and not pick up a few things about plumbing.

Amy: Do you think it's possible you might enjoy being on your own for a little while?
Sheldon: It's hard to say. I've never really lived by myself. What if I become strange and eccentric?
Amy: I'll love you no matter what.
Sheldon: Howard Hughes saved his urine in milk bottles.
Amy: We'll cross that bridge when we come to it.

Sheldon: Stuart, wait. I do know what it feels like to be left out.
Bert: I know how it feels, too.
Sheldon: All right, this is about me and him; you're not part of it.

Amy: Sheldon, your mother's an attractive woman. You need to get used to the fact that men are going to be interest in her.
Sheldon: Well, and you need to drive the car and mind your business.
Amy: I will not have you be disrespectful to me.
Sheldon: What- you're not my mother.
Mary Cooper: Don't you be disrespectful to her.
Sheldon: Yes ma'am.
Mary Cooper: You'll get there. You've just gotta put some zing on it.

Sheldon: We seem to be moving on to the annual coitus portion of your birthday festivities.
Amy: Is that okay?
Sheldon: I didn't put on my come-hither plaid PJs for nothing.

Mary Cooper: Shelly, how do I put this? By your third birthday, you had memorized over a thousand different kinds of trains, and I never imagined a woman getting aboard any of them.
Sheldon: What, so - You thought I was going to be alone for the rest of my life?
Mary Cooper: No! Just for the middle part. 'Cause at the end I assumed there'd be nurses.

Leonard: Sheldon, this is not a big deal. It's a little white lie, everyone does it.
Raj: Not me, I'm a 100% honest in all of my relationships.
Howard: And how single are you right now?
Raj: Eating-cake-on-the-toilet single.

Sheldon: Being with Amy has awoken the sexual creature within. When I see a pretty gal walking down the street, I think, "hubba hubba" like any other guy.
Penny: You kiss your mother with that mouth? 'Cause it's fine.

Howard: You know, maybe before our meeting we should talk to a lawyer.
Leonard: That's not a bad idea.
Raj: Well, you must have someone in your family that's a lawyer.
Howard: Why? Because I'm Jewish? That's like me saying, "Hey, you're Indian. Doesn't your cousin work in a call center?"
Raj: My cousin does work in a call center.
Howard: And my cousin's a lawyer.

Susan: Penny, I don't know what I was worried about. Your friends are just lovely.
Penny: Oh, thanks, Mom.
Susan: Although that Sheldon is a bit peculiar.
Penny: Is he? I never noticed.
Wyatt: He reminds me of that turkey we had who drowned looking up at the rain.

Amy: All right, you can open your eyes. I thought I'd let Harry Potter make things hotter.

Penny: You want food?
Bernadette: Yeah, breastfeeding burns, like, 5,000 calories a day. (To Amy) Do not touch that phone!

Sheldon: I admire you, Leonard.
Leonard: Really, why?
Sheldon: You're happy with who you are. You don't get jealous of other people. Instead of being weighed down by ambition, you just float along like a dead body in a river.
Leonard: I couldn't just take the compliment. I had to ask why.

Penny: You know, when Leonard's feeling anxious, I make him take a long walk.
Amy: Does that help?
Penny: For a while, then he comes back.