Howard: Raj's parents probably split up because of Raj.
Bernadette: What?
Howard: You always say the children aren't to blame, but (holds up a Raj coaster; chuckles) come on!

Sheldon: I was not panicked, and I am not overly attached to Leonard.
Leonard: You were so worried that you smashed your face trying to check on me. You looove me.

Penny: When Leonard comes out, he is not gonna feel great, so please don't give him a hard time.
Amy: Penny has a good point. This is like the man in the supermarket with the goiter on his neck. Whatever you're thinking, just keep it to yourself.
Sheldon: It was like a grapefruit.
Amy: And I'm sure he knew that before you held a grapefruit up next to it!

Howard: Lots of people wear matching pajamas who aren't dating.
Raj: Like who?
Howard: Like you and your dog.
Leonard: Don't rule out the dating.

Sheldon: Sorry, kid, you got it worse than a gibbon.

Penny: That, believe it or not, is my prom dress.
Bernadette: Wow, you still have it? I just assumed it was balled up in a corner of a barn somewhere.

Penny: What kind of teenager did you think I was?
Bernadette: Slutty.
Amy: Easy.
Penny: The word is 'popular'.

Bernadette: How was your prom? Did you go?
Amy: No, but I was on cleanup crew.
Penny: Aw, that's sad.
Amy: No, it was okay. The DJ let me dance one slow dance with my mop before he shut down. Whenever I see a bucket of dirty water, I still hear Lady in Red.

Amy: You went to seven proms?
Penny: Yeah. Let's see, four "under the seas", two "enchanted evenings", and one night to remember - that I can not remember for the life of me.

Raj: Ever since I saw Pretty in Pink, I've wanted to go to an American prom. But then I saw Carrie and did not want to go to an American prom. Then I saw Never Been Kissed and I'm back on the prom bandwagon. This prom things been a real rollercoaster.

Raj: Did you go to your prom?
Sheldon: No. I had a date with a proper education. Instead of a tuxedo, I dressed myself in good habits. Instead of spiked punch, I enjoyed the intoxicating flavor of knowledge. Instead of dancing in a gym, I shook my bootie to the seductive rhythms-
Penny: Okay, okay.
Sheldon: -of AP calculus.

Bernadette: Why can't he take your mom? You took her to your prom.
Howard: I didn't take her. She was a chaperone.
Bernadette: I saw a picture of you two dancing together.
Howard: Well what was I gonna do? They were playing our song.

Stuart: I'm not bringing your mother. I have a date.
Howard: Oh, so now you're cheating on my mother.

Stuart: What are you talking about? There's nothing weird going on between me and your mother.
Mrs. Wolowitz (o.s.): Stewie, your bath is getting cold!

Sheldon: I think I've come up with the perfect way for us to enjoy it.
Penny: Great. How?
Sheldon: We pretend we're aliens. We pretend we're aliens. I'm not the best at reading facial cues, but I'm gonna say that you love it and wanna hear more.