Leonard: Just tell me the truth, Mother. Was my whole childhood just one big experiment?
Beverly Hofstadter: Of course not, dear. It was thousands of small experiments.
Leonard: So that's all I was to you, a-a test subject?
Beverly Hofstadter: No, you were my baby and I found you fascinating.
Leonard: Really?
Beverly Hofstadter: Yes, watching you develop, tracking your progress. I know I'm not the warmest of parents, but it was time we spent together, and, honestly, those are some of my fondest memories.
Leonard: When did you stop?
Beverly Hofstadter: Oh, I can't tell you. The experiment isn't over.

Leonard: Well, uh, okay, um, I dont want to get back together with Penny. We tried it, it was crazy, it didn't work, but I can't deal with the fact that she slept with my friend Raj. And then I find out that Raj's sister Priya, who I've been going out with for eight months, is moving back to India. So I'm just completely confused and alone.
Beverly Hofstadter: I understand.
Leonard: Got any advice?
Beverly Hofstadter: Yes. Buck up.
Leonard: Excuse me. You're a world-renowned expert in parenting and child development, and all you've got is buck up?
Beverly Hofstadter: Sorry. Buck up, sissy pants.

Beverly Hofstadter: So, Howard, have you and Rajesh finally summoned the courage to express your latent homosexual feelings towards one another?

Beverly Hofstadter: She doesn't have much in the way of career prospects, and don't make her responsible for her own orgasms as well.

Stuart: Where are the kids?
Howard: I thought they were with you.
Stuart: What? No!
Howard: I'm kidding. They're at daycare.
Stuart: What about me makes you think my heart can handle that joke?

Raj: Where are the kids?
Amy: Oh, Sheldon's helping Howard give them a bath.
Raj: Hmm. So you really think you can trick Sheldon into liking babies?
Amy: I slept with him. I married him. You want to bet against me?

Raj: I never thought I would see Sheldon enjoying himself around babies so much.
Amy: Yeah, how about that?
Raj: So he just happened to stumble upon a book about experimenting with them the same day we were hanging out with Howard's kids?
Amy: Yep, don't overthink it.