Amy: A team of physicists confirmed super-asymmetry. Our paper was right. We did it.
Sheldon: We did it?
Amy: We did it.
Sheldon: We did it.
Both: We did it! We did it! We did it!
[in the hallway:]
Penny: Aw, remember when they only did it on her birthday?

Penny: And Leonard just stood there with a big, dumb smile on his face, like he was watching a puppy and a monkey make friends.
Bernadette: Well, I can see how he'd be flattered to be asked.
Penny: It's not flattering. It's creepy.
Amy: Well, something can be both flattering and creepy. You know, just the other night, Sheldon said that my feet looked like Richard Feynman's hands.

Penny: Really? So you'd be okay if someone wanted to use Sheldon as their sperm donor?
Amy: Oh, absolutely not. I am the only handmaid in this tale.

Bernadette: So Leonard's really considering this?
Penny: Yes. We got in a huge fight about it. He said, well, if I don't want to have his baby, then why shouldn't someone else be able to? Do you believe that? What?
Bernadette: Well, there is a deep-seated biological drive to pass on your genes. It's only natural.
Penny: So you're on his side?
Amy: Well, viewing Leonard as a mammal, it's perfectly understandable.
Bernadette: But viewing him as your husband, he stinks.
Amy: And we hate him.

Sheldon: They wanted you?
Leonard: Yes, Sheldon, they wanted me. I'm smart. I'm nice.
Sheldon: I'm smart. I'm nice. And I can eat cheese without clearing out a room.
Leonard: Are you upset he didn't ask you?
Sheldon: Of course not. I just think it's interesting that of all the people he knows, he thinks you're the best choice.
Leonard: Well, he does. I don't see why Penny is so against this.
Sheldon: Well, perhaps Penny's worried that you haven't considered the emotional toll of knowing there's a child out there who is biologically yours but not actually yours.
Leonard: Wow, that's really insightful.
Sheldon: Yeah, I'm taller than you and I don't have asthma.

Anu: But I warn you, I just got out of a weird relationship, and I might complain about my ex a lot.
Raj: Maybe he's being weird because he doesn't know how to ask for his ring back.

Leonard: All right, look, um I'm sorry that we fought before. I know this is a really unusual situation, and if you don't want me to do it, I won't.
Penny: Really?
Leonard: Yeah. We're a team. We're in this together.
Penny: I'll be right back.
Leonard: What is that?
Penny: It's a sample cup.
Leonard: Really? 'Cause it looks like the top off the NyQuil bottle.
Penny: It's the closest thing I could find. It's a gesture. Shut up.

Penny: They couldn't have picked a better person. [Leonard chuckles and picks up his phone] Are you calling Zack?
Leonard: No, Sheldon. Would you say that last part one more time?

Penny: So, Marissa, how did you guys meet?
Marissa: Oh, it's a pretty funny story. We met in a bookstore.
Leonard: That is funny.
Zack: Yeah, I was just there using the bathroom, but this one had a stack of books, like, this tall.
Penny: Oh. So, you really like to read?
Marissa: Oh, no. I work there.
Zack: Yeah, she is super smart. Seriously, you name, like, any book, she'll tell you if she's heard of it. Go on, try her.
Leonard: Oh, uh, well, uh Catcher in the Rye.
Marissa: Nope.
Zack: Look at that, Penny. I guess we both like nerds.

Leonard: So, uh, we gonna take this thing out?
Zack: Nah. It's a little choppy tonight.
Penny: Yeah, that's okay. This is nice, sitting under the stars. It's actually kind of peaceful.
Leonard: Well, it's a beautiful boat.
Zack: Thanks, man. We love it.
Marissa: Although, he's so tall he bangs his head almost every time he goes downstairs.
Zack: After the first couple, you don't even feel it.

Leonard: Are you jealous?
Penny: I know, I know, I shouldn't be. He's super sweet. I should be happy for them.
Leonard: Oh, it's driving me crazy, too.
Penny: Really?
Leonard: Yes. I was trying to pretend like it wasn't so you wouldn't think I was petty.
Penny: Wha-- turns out we're both petty.
Leonard: I love you so much.
Penny: Aw.

Zack: So listen, I got to be honest. We sort of have another reason for asking you here.
Marissa: We want to have a baby, but we can't do it on our own.
Zack: It could be because of the game me and my frat brothers used to play where we kicked each other in the balls over and over. But the doc says there's no telling.
Marissa: We just don't know.
Leonard: Huh. You went to college.

Marissa: And Zack's always admired you because you're the smartest person he knows.
Penny: Okay, whoa, whoa. Whoa, whoa. You know, this has been such a nice evening. Let's all just stop before anyone says any more things.
Zack: Leonard, would you be the father of our baby?
Penny: Aw, you said a thing.

Leonard: Wow, this is really flattering.
Penny: And also really weird, right?
Zack: Oh, just to be clear, you don't get to you know.
Leonard: No, I - I got it.
Zack: Just because I slept with your wife doesn't mean you get to sleep with mine.
Penny: We we get it, but thank you for saying it out loud.
Zack: You're welcome.

Marissa: I know it's a big ask, but it would mean so much to us.
Zack: Yeah, and we really don't want a stranger's, you know-
Leonard: I know.
Zack: -sperm.