Leonard: He startles easily, so, please, no flash photography.

Amy: There was water everywhere. It was such a mess.
Leonard: That stinks. How long are you out of the apartment?
Amy: About five weeks.
Penny: Ugh! Did you lose anything valuable?
Amy: Well, the pipe was over my closet, so all my clothes are gone.
Penny: Oh, so nothing. Great.

Amy: So, is that a yes?
Sheldon: Not yet. How will I learn if I'm comfortable living with Amy or just comfortable because I'm in my own apartment? Now, if this experiment is going to be valid, I suggest a neutral environment.
Penny: Where would you go?
Sheldon: Well, ideally, an enclosed, self-sustaining biodome in New Mexico. Where we would eat crops fertilized with our own waste.

Raj: I have to say, I am happy with your ob-gyn.
Howard: Cool. 'Cause she says you're doing a great job as "weird friend who doesn't have to be at every appointment."

Penny: You know, I'm very proud of you for trying to live with Amy.
Sheldon: Oh, thank you. Of course, the ideal way to conduct this experiment would be with four pairs of identical Sheldons and Amys. One pair that was neither dating nor living together. One pair that was dating but not living together. One pair that was living together but not dating. And then, of course, one pair that was living together and dating. Although, with that many Sheldons, it'd be such a party, we'd never get anything done.
Penny: That was a cute story.

Penny: So, uh, what did you want to ask me?
Sheldon: Well, you've lived with your significant other for some time. I would like this experiment to go well. Are there any insights you can share?
Penny: Mm. Well, the biggie is, if she has an insane roommate, kick him out as soon as possible.
Sheldon: You know, Leonard and I were very happy before you came along.

Sheldon: Enjoy having the place to yourselves.
Leonard: You enjoy your mission to boldly go where no man has gone before.
Sheldon: It's Penny's bedroom. Plenty of men have gone before.

Bernadette: Is it weird we don't?
Howard: I don't know. Maybe the surprise will make it more fun. Like magic tricks. Remember how disappointed you were when I explained the never-ending hanky?
Bernadette: I was disappointed to see the man I was engaged to pulling rainbow scarves out of his fly.
Howard: But how delightful was it when I pulled out a bouquet at the end of those scarves? It'll be the same thing when the doctor pulls a beautiful surprise out of you.
Bernadette: Everyone said I could do better.
Howard: But you didn't listen, and presto change-o, my baby's inside you. Ta da!

Amy: Sheldon? I know we took coitus off the table, but I was wondering how you feel about other forms of intimacy, such as snuggling.
Sheldon: Well, it's funny you should ask, because I was wondering how you'd feel about separating the two of us with a pillow wall.

Leonard: That's it. It's Sheldon's bedtime. He is in for the night.
Penny: Wow. I cannot believe we are alone in our own apartment.
Leonard: (chuckles) It's weird. This must be how parents feel when their kid goes off to college. Unless they feel sad, then it's different.

Amy: Sheldon, maybe living together is a bad idea.
Sheldon: But what kind of scientists would we be, drawing a conclusion after only 12 hours of data?
Amy: The kind who almost put a pillow over your face last night.

Sheldon: Well, if you are so protective of the scientific method, perhaps we should use the next five weeks to finish what we started.
Amy: Well, for science, maybe I will!
Sheldon: For science, maybe you should!
Amy: Fine!
Sheldon: Fine!
Amy: Good.
Sheldon: Great.
Amy: Do you want to go to our place and make out?
Sheldon: Does Stephen Hawking roll through the quad?

Sheldon: Yeah, but what happens when we each get a peek behind the curtain? I mean, she's never even seen me unshaven.
Leonard: You just shaved yesterday. You're good for three months.

Amy: So, technically, I'd be moving in with my boyfriend?
Penny: I guess so. I'd finally get to live alone with my husband.
Amy: Oh, my, this is a big step.
Leonard: Mm-hmm. For two of us, it's in the right direction.

Sheldon: What if living together kills the romance?
Penny: Okay, you guys had sex one whole time. Nothing can put out a fire like that.