Sheldon: I really did think you looked pretty.
Amy: You did?
Sheldon: Yes. So much so that I started to panic.
Amy: Well you can relax. Just because you think I look pretty doesn't mean we have to spend the night together.
Sheldon: Were you hoping we would because it's prom?
Amy: I'm always hoping. But tonight, I just wanted to have a nice time with you. Maybe dance with someone who has arms.

Sheldon: There's no denying that I have feelings for you that can't be explained in any other way. I briefly considered that I had a brain parasite, but that seems even more far-fetched. The only conclusion was love.

Stuart: Oh, so she's good enough for Howard but not for me?
Howard: Yeah.
Bernadette: Yeah. Go have weird relationships with your own mother and cousin. This is his turf.

Raj: Okay, here we go. [to Leonard & Penny] Say cheese. [to Sheldon & Amy] Say cheese. [to Howard & Bernadette] Say cousin.

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

Sheldon: Thank you for understanding.
Amy: Of course I understand. Sheldon, there's something else I've been wanting to say, but before I do, I just. I want you to know you don't have to say it back. I know you're not ready and I don't want you to say it just because social convention dictates -
Sheldon: I love you, too.
Amy: You said it.

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.

Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.

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!

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.

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

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

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.

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.