Leonard: I would pull this car over and kick you out, but if Penny dumps me, you're all I got.

Sheldon: Amy is free. She had a harp lesson on Saturday, but it got canceled. Boy, when you take an interest in people, you really uncork a geyser of nonsense.

Amy: Aww, I remember signing our first Relationship Agreement.
Sheldon: You seem to be forgetting the "no nostalgia" clause.

Sheldon: At our age, why don't we call it man's night?
Leonard: Because we just spent our allowance on comic books.

Penny: Pink wine and pizza bagels? It's like eighth grade all over again.

Bernadette: Things going well with you and Sheldon living together?
Amy: Better than ever. He asks about my day, takes an interest in my life. He's like my boyfriend in college, except he's real, so people can see him.
Bernadette: I've been seeing him for years. I'm still not convinced he's real.

Raj: No offense to her father, but he's not an MIT-trained engineer. Thinking and building is what you do.
Howard: MIT's motto is "Mind and Hand," which just so happens was also my motto as a lonely teenager.

Leonard: It's not that I'd stopped trying, it's just how relationships progress. They start with infatuation, but over time mellow into something more comfortable.
Sheldon: Hmm. Yeah, you're right. It's like when I first encountered the Pythagorean Theorem. You know, I was blown away that the square of the hypotenuse was the sum of the squares of the opposite sides. Yeah, but now I'm just like "eh."

Raj: It looks like a map from Dungeons & Dragons.
Howard: Mm. Except the creature in the crib is a level-nine poop monster.

Leonard: What do you say?
Sheldon: I get to write a contract? I say, let's get this party of the first part started!
(Amy enthusiastically laughs)
Penny: Do you really think that's funny?
Amy: It's in our agreement. I have to laugh.

Amy: I'll miss you.
Sheldon: I'll miss you, too.
Amy: I'll miss you more.
Sheldon: Well, if X equals the amount that you'll miss me, then I'll miss you X plus one.
Amy: (giggles) If you miss me X plus one, I'll miss you open parentheses X plus one, close parentheses to the second-

Penny: Is it normal for the husband to kind of completely stop giving a crap?
Bernadette: Uh-oh, what's going on?
Penny: Well, Leonard used to do all these things, like bring me flowers and wear pants.

Howard: Yeah, got to get her hooked on TV, or someday, she'll want me to play outside.

Sheldon: So, tell me, do you have any plans for the weekend?
Leonard: Are you gonna laugh at the answer?
Sheldon: Only if the answer is "shopping for baby shoes."

Bernadette: It's okay, Howie never has on pants. The Domino's guy brings the pizza like this now. (covering her eyes)
Amy: Well, Sheldon always has his pants on. I don't think I could pick his knees out of a lineup.