Penny: What is this picture?
Amy: Oh, it's an MRI of our brains photoshopped to look like they're kissing.
Sheldon: Is it too sexy?
Penny: It's too something.

Raj: Boy, seeing them all together like that has got my biological clock ticking like crazy.
Penny: Yeah, I don't think men have-
Raj: I do.

Bernadette: Sorry I talked about my kids the whole time.
Amy: Oh, don't worry about it. I mean, besides you cutting up my meat for me, it was a lovely lunch.

Amy: Well, these are positive changes. Studies with rats show that new mothers are more sensitive to danger, better at multitasking and bolder in the pursuit of food.
Bernadette: I did stick a couple lamp chops in my purse.
Amy: So that's what I was smelling.

Amy: You're right. We both do important work. I'm trying to map the structures of the brain and you're trying to convince people that itchy hair is a real thing.
Bernadette: It is a real thing! It happens to be a side effect of our cholesterol drug.

Raj: I mean he only drinks milk. Like, where are the colors coming from?

Sheldon: I also have a pretty cute picture to share.
Howard: What is that?
Sheldon: An equation. Isn't it perfect? Sometimes I just stare at it, and I think "I can't believe that came out of me."

Sheldon: Why did you lie to me?
Leonard: I don't know. It just seemed funny at first and then the longer it went on, funnier it got.

Amy: Look, even though your brain is different, in many ways, it's better.
Bernadette: But were you bored?
Amy: Of course not.
Bernadette: You're lying.
Amy: Which you can tell, because your maternal brain is better at sensing nonverbal cues.
Bernadette: Now you're just being condescending.
Amy: Look at you, two for two.

Penny: Hey, where you been?
Leonard: Uh, just hanging out with the guys.
Penny: They still mad at me?
Leonard: Uh, they were, but then I was like, "Hey," and they were like, "What?" and I was like, "You know," and they were like, "Okay."
Penny: You're a good husband.
Leonard: Well, it's not for me to say, but you just said it, so you're probably right.

Bill Gates : Wait, I know you.
Leonard: No, you don't.
Bill Gates : Yes, I do. You were waiting for me at my hotel. You ruined my tie.
Penny: Wait, what? What's he talking about?
Leonard: Uh, he, uh-- obviously, he's kidding. That's a, that's a good one, Bill. I got to go.

Sheldon: Anyway, I'm proud of you. And I'm going to try to do a better job of sharing the spotlight because we're a team. You know? Much like the Dodgers. If they had superpowers, and fought crime. And Thor was in them.

Sheldon: Don't worry. I don't expect you to bear them all. I'm sure we can find a suitable uterus to rent. [looks to Penny]
Leonard: No!
Penny: Uh-uh!
Amy: We weren't thinking about you.
Sheldon: Of course not. (grunts) I am going to the kitchen. Can I get anybody anything? Penny, nice glass of milk and a multivitamin?

Amy: I've always liked the name Elliott.
Leonard: Sorry, can't have it. That's my boy name.
Amy: I said it first.
Leonard: It's not like calling dibs.
Amy: Yes, it is. It's exactly like that. Dibs on Elliott.
Leonard: I'm just saying, we might get there first. You only have sex once a year. I'll probably have sex tonight. [Penny looks at Leonard] Fine, you can have Elliott.

Amy: Why didn't you tell me?
Sheldon: 'Cause I wanted to make sure that you loved the man, not the office.