Mrs. Wolowitz: Who's there? Are you a sex criminal?
Howard: Sex criminals don't have key, ma!
Mrs. Wolowitz: Where were you so late?
Howard: I was out with Bernadette
Mrs. Wolowitz: I know what that means, I watch Dr. Phil. I hope to God you used a condom.
Howard: I am not having this conversation with you, ma.
Mrs. Wolowitz: God forbid you get one of them fancy sex diseases.
Howard: Nobody has a disease!
Mrs. Wolowitz:I hope not. I share a toilet with you. Is that what you want, to give your mother herpes?

Amy: So, you feeling better?
Penny: Not really.
Amy: Sheldon, you have a guest who's upset.
Sheldon: I'll make tea.
Penny: Sweetie, it's OK. I don't want tea.
Sheldon: It's not optional.

Sheldon: Priya, if you're experiencing any tension or awkwardness, it may stem from the fact that Leonard and Penny used to, if I might quote Howard, "Do the dance with no pants".

Amy: Thanks to you, I just made a rhesus monkey cry like a disgraced televangelist.

Raj: You heard me, I forbidded it.
Priya: Forbidded it?
Raj: Forbayded it?

Sheldon: Just keep in mind, should you ever need a slightly apathetic, tertiary friend, I stand at the ready.

Amy: Well, granted Penny your secondary sexual characteristics are reasonably bodacious but Priya is highly educated, she's an accomplished professional and she comes from the culture that literally wrote the book on neat ways to have sex. Whereas you, on the other hand, are a community college drop-out who comes from the culture that wrote the book on tipping cows.

Amy: I came as quickly as I could.
Penny: Ok, why?
Amy: To comfort you, of course. Sheldon told me about Leonard dating Rajesh's sister, so I high-tailed over here to pick up the pieces of your broken heart.
Penny: Amy, I'm fine.
Amy: You don't have to be strong for me. Now, let's talk about Priya, that man-stealing bitch.

Sheldon: The Hindu Code of Manu is very clear in these matters. If a woman's father is not around, the duty of controlling her base desires falls to the closest male member of her family. In this case, Raj. The code also states that if she disobeys, she will be reborn in the womb of a jackal and tormented by diseases. If true, that seems like an awfully large gamble given that the prize is Leonard.

Sheldon: Leonard, social protocol states when a friend is upset, you offer them a hot beverage, such as tea.
Howard: Tea does sound nice.
Sheldon: You heard the man, Leonard. While you're at it I am upset we have an unannounced house guest, so make me cocoa.

Sheldon: Point of inquiry. Given that Leonard is your secondary friend and Koothrappali is your primary friend, why didn't you seek refuge under his roof?
Howard: There's no room. His sister is staying with him.
Leonard: Wait, wait. What?
Sheldon: Cocoa, Leonard. Focus. I'm down in the dumps here.

Amy: It seems like the appropriate thing to do when one's best friend finds herself replaced by a smart, beautiful woman with the smouldering sexuality of a crouched Bengal tiger.

Sheldon: Don't worry. As you tertiary friend I'm prepared to step in and comfort you.
Howard: It's not really necessary.
Sheldon: Ah no. I'll finish making the tea while you narcissistically ramble on about whatever's troubling you.
Howard: Thanks.
Sheldon: That's what tertiary friends are for.

Bernadette: Wait a second. I'm doing your laundry?
Howard: Well, honey, it's not gonna do itself. Oh, before I forget. Tomorrow morning, you're driving me to the dentist.
Bernadette: I have to take you?
Howard: You don't have to take me. You get to take me.
Bernadette: Wait a minute. Are you telling me your mother usually takes you to the dentist?
Howard: It's not weird. There's lots of kids there with their moms.

Penny: I'm sorry. I didn't know you had company. I don't want to impose.
Sheldon: No, no. It's not an imposition. At this point, in our ecosystem, you are akin to the plover, a small scavenging bird that eats extra food from between the teeth of crocodiles. Please, fly into our open maw and have at it.

Howard: Listen, my mom's going to Palm Springs to visit her sister. That's two whole nights in a row I can sleep over with you all the way to morning. Unless the desert air dries out her sinuses, in which case I'll have to schlep out there with the big humidifier.
Bernadette: That's it? That's your big solution to all of our problems? If your mom's nose holds up, we get two nights together?
Howard: Isn't that great?

Penny: So, what is all that stuff?
Amy: This is a portable electroencephalogram. I'm doing research on emotions and brain activity. So when you start crying, I can see which region of the brain is activated. Then I'm going to stimulate the analogous area in the brain of a rhesus monkey and see if he cries. Cool, huh?

Howard: I choose you.
Bernadette: Really?
Howard: Yep. I moved out of my mother's house. Cord is cut. I'm all yours.
Bernadette: What did she say when you told her?
Howard: I don't know. She hasn't responded to my email yet.

Bernadette: I can't believe we're finally living together.
Howard: Yeah. You know what would make this moment perfect?
Bernadette: What?
Howard: A little snack. You got any string cheese?
Bernadette: No. I, I might have some cheddar.
Howard: Not as good. You can't make strings with it. Remind me to put it on your shopping list.

Howard: You have hypo-allergenic detergent?
Bernadette: No.
Howard: Better put it on the list. If you wash my underwear with regular soap, I get little red bumps on my tuchus.

Bernadette: I can't believe this.
Howard: What? It's fun. If I have no cavities, afterwards, we go out for a treat.
Bernadette: All right, Howard, let's get something straight right now. I'm not going to be your mother.
Howard: Whoa, whoa, whoa! Where did that come from?

Penny: I smell Chinese food.
Sheldon: It's actually Thai. You're slipping.

Penny: Are Leonard and Priya here?
Sheldon: They went to Catalina for the weekend.
Penny: Oh. Where's Raj?
Sheldon: At home, forbidding it.
Penny: How about Howard?
Sheldon: I'm given to understand his mother grounded him for running away.

Raj: Why are you holding hands? I forbid you to hold hands.
Priya: Rajesh, you know Leonard and I spent the night together.
Raj: Yeah, but you were just sleeping, because I forboded you to have sex.
Leonard: The word is forbade.
Raj: Are you sure? That doesn't sound right.

Raj: It's completely inappropriate for a single woman to entertain a man in private. If you insist on talking, you must do it on the couch! All right, you may talk in the bedroom, but I want this door to remain open! All right, just this once you may close the door. But keep in mind I'll be right out here monitoring the situation! (Makes a phone call) Oh, damn it. Leonard, when you get this message, call me. (Makes another call) Priya, this is your brother. When you get this, tell Leonard to check his voicemail.

Bernadette: Howard, have you ever considered us living together?
Howard: Boy, I don't know. You, me, Ma living under the same roof?
Bernadette: No, I mean just you and me. You can move in here, or we can find a place.
Howard: I've got a better solution.
Bernadette: What?
Howard: We wait for my mom's heart to explode from all the salt she eats. Then we just stick her in the ground, flip her mattress and move into the big bedroom.

Howard: Well, gotta go.
Bernadette: Oh! Already? Why don't you stay over?
Howard: Well, I'd love to, but you know my mother needs me in the morning.
Bernadette: Please, I think the woman can manage to put a wig on by herself.
Howard: It's not just the wig. It's pinning her hair up, drawing on her eyebrows. It's a two-person job.

Howard: What's so funny?
Bernadette: Nothing. Just thinking about the noises people make during sex.
Howard: I do sometimes get a bit carried away, don't I?
Bernadette: It's cute. You sound a little like a drunken monkey. Ooh-ooh-ooh-ooh!
Howard: You know it's meant as a compliment.
Bernadette: That's how I take it.

Penny: Today I drove to Van Nuys for an audition I thought was going to be for a cat food commercial. Turned out to be for porn.
Sheldon: Did you get the part?
Penny: I didn't do the audition.
Sheldon: Given the state of your career, can you really afford to be picky?

Penny: Ooh, I thought I smelled pizza.
Sheldon: That's remarkable. If pepperoni were an explosive substance, you could replace German shepherds at our nation's airports.

Raj: Leonard, I swear to God, if you sister ever comes to town, I shall have my way with her.
Leonard: my sister's thirty-eight and married.
Raj: All the more shame that will fall upon the house of Hofstadter.

Raj: Penny, you became disenchanted with Leonard as a lover. Would you please tell my sister why?

Howard: Big fight with my mother.
Leonard: Still arguing over which CSI is the best?
Howard: No, we agreed they all have their merits. This was about Bernadette.