Leslie: Anyway, I just figure it's time to slow things down and who better to slow things down with than you?
Leonard: Oh, I'm flattered. So, how do you suggest we proceed?
Leslie: Your place, we'll order Chinese, you'll rent a movie, artsy but accessible, then light petting, no coitus.
Leonard: Sounds fun.
Leslie: I'll leave the details up to you, I think it's better if you assume the male role.
Leonard: Thank you, that's very thoughtful.
Leslie: Great. Call me!

Leslie: Oh. So, how many children do you think we should have?
(Leonard splutters)
I'm sorry, that was a little abrupt.
Leonard: A little.
Leslie: I mean there are so many things to talk about before we discuss reproduction.
Leonard: I sure hope so.
Leslie: Besides shortness, what genetic weaknesses run in your family?

Leonard: Well, I think tonight was a very good start.
Leslie: Me too. You're sure you're okay postponing intercourse until our relationship is past the initial viability test?
Leonard: No problem, I'm very skilled at postponing intercourse. So I guess I'll call you and we'll arrange another evening.
Leslie: Yes. I believe protocol dictates that you wait a minimum of 18 hours before you call so I'm not repulsed by your cloying eagerness.
Leonard: Sure.
Leslie: Again, it's your decision, you're the man.

Leslie: Hey fellow scientists. Sheldon.

Leslie: You agree with me, right, loop quantum gravity is the future of physics.
Leonard: Sorry Leslie, I guess I prefer my space stringy not loopy.
Leslie: Well, I'm glad I found out the truth about you before this went any further.
Leonard: Truth, what truth? We're talking about untested hypotheses, uh, it's no big deal.
Leslie: Oh, it isn't, really? Tell me Leonard, how would we raise the children?

Leonard: I guess we let them wait until they're old enough and let them choose their own theory.
Leslie: We can't let them choose, Leonard, they're children!

Leonard: You could be Batman?
Sheldon: Yeah. I'm Batman. See?

Howard: How's the air matress?
Sheldon: It's okay, if you don't mind sleeping on a bouncy castle.

Leonard: What happened to him?
Howard: He wouldn't sleep so I gave him a glass of warm milk with a handful of my mother's Valium in it. Tag you're it!

Sheldon: And you thought the opposite of stupid loser was a Community College Graduate?

Sheldon: I drank milk that tasted funny.

Wolowitz: Qu'est-ce que 'sup?

Wolowitz: Leonard, how was your date?
Leonard: Bite me!

Sheldon: When I try to deceive I have more nervous ticks than a lime disease research facility. It's a joke. It relies on a homonymic relationship between the tick the blood sucking arachnid, and tick the involuntary muscular contraction. I made it up myself.

Penny: So, do you think that if Leonard and I keep dating, Leonard would get bored with me?
Sheldon: That depends.
Penny: On what?
Sheldon: Do you have a working knowledge on Quantum Physics?
Penny: No.
Sheldon: Do you speak Klingon?
Penny: No.
Sheldon: Do you know any card tricks?