Tam: It got a little uncomfortable.
Sheldon: Why is that?
Libby: Libby's got feelings for me, but I think it's better we just stay friends.

Adult Sheldon: The addition of Libby brought a level of sophistication to our lunchtime discussion.
Her mom also packed extra string cheese, which is a well-known social lubricant.

Mary: Well, Sheldon's been spending quite a bit of time with this Libby girl, lately.
George: Yeah, so?
Mary: So isn't he a little young to be hanging with teenagers?
George: Oh, he's only young on the outside. Inside, he's an old man.
Mary: I'm being serious.
George: So am I. And with that bow-tie, he's old on the outside, too.

Meemaw: So what do you think, George? Is it time to have "the talk" with him?
Missy: What talk?
Mary: No talk. Nobody's talking.
Sheldon: If "the talk" is in regards to human reproduction, I already understand how that works.
Mary: How do you know that?
Missy: I told him.
Mary: Oh, Lord.

Mary: And now he wants to see a movie in Houston with them.
Meemaw: Why Houston?
Mary: I don't know, it's in MixMax or something.

Mary: I gave it a lot of thought, and I'm afraid I can't allow you to drive to Houston with your friends.
Sheldon: Why?
Mary: Well, honey, you're still a little boy.
Sheldon: I don't think it's right. I'm not a little boy. I'm a high school student.
Mary: I'm sorry, I made up my mind. If you'd really like to see this movie, I'm willing to drive you. Maybe we could meet your friends there.
Sheldon: I don't want my mommy to take me.
Mary: Well, then, you're not going.

Mary: How's it going?
George: Well, I think I figured out the problem.
Mary: What is it?
George: I'm a terrible mechanic.

Mary: I hope you'll forgive me, I just wanted to meet the person driving my nine-year-old son to Houston.
Libby: I understand.
Tam: Me, too.
Mary: I wasn't talking to you, Tam.

Mary: She is almost twice your age.
Sheldon: There are people five times my age that are stupider than me.
Mary: This is not about being smart.
Sheldon: What else is there?
Mary: Well there's other kinds of maturity.

Missy: What's up?
Mary: None of your business.
Missy: Why is he crying?
Mary: Again, it's none of your business. Please go.
Missy: Fine. Celeste and I know when we aren't wanted.

Sheldon: Are you saying that without geology, there'd be no theory of evolution?
Libby: Charles Lyell taught Charles Darwin the Earth was much, much older than anyone thought, which gave Darwin the courage to figure out all species evolved over billions of years.
Sheldon: That's good. I can use that to humiliate my pastor at Sunday school.

Libby: You have a beautiful home.
Sheldon: Thank you.
Mary: Thank you.

Mary: Shelly, you okay?
Sheldon: No.
Mary: You want to talk about it?
Sheldon: No.
Mary: You want me to leave you alone?
Sheldon: No. I thought Libby and I were equals, but she thinks of me as a child.
Mary: I'm sorry, baby.
Sheldon: Calling me that isn't helping right now.
Mary: Right. Sorry.

George: Hey, Georgie, if you ever find a girlfriend, maybe you can go on a double date with your brother.
Mary: She's not his girlfriend.
Georgie: And I can find one I'm just not looking.
George: We gotta get that Sports Illustrated swimsuit issue away from him before he's ruined forever.