The Good Guy Fluctuation
& Sheldon: All right, all right. I see what’s going on. A little pre-Halloween hijinkery.
& Sheldon: A ghostly moan, a rattling of chains, a witch’s cackle. The trifecta of haunted house clichés.
& Sheldon: “See you in hell Sheldon.” The most frightening thing about that is the missing comma.
& Howard: Who had money on “faints”?
Raj: I had “pee his pants.”
Leonard: Hang on. Looks like everyone’s a winner.
& Alice: Hey, if I pretended to hit on you, could I distract you enough to sneak it away?
Leonard: Yes, but you’d be using your superpowers for evil.
Alice: Damn, I’m forbidden by my Kryptonian father to do so.
& Leonard: More Halloween candy? Didn’t you just buy a bunch of it yesterday?
Penny: Oh. Yeah. That’s gone. It’s a rough month when Halloween and PMS hit at the same time.
& Penny: Want some mac and cheese?
Leonard: No. Lactose. Gas.
Penny: Glass of wine?
Leonard: No. Sulfites. Migraines.
Penny: Okay, well, I’d offer you Halloween candy, but that’s gone.
& Penny: So, what’s up?
Leonard: Okay, we used to go out, right?
Penny: Oh, my God, that’s where I know you from.
& Leonard: Okay, uh... here it is. Is it cheating if a guy has a girlfriend...
Penny: Yeah, probably.
& Penny: Did you guys do it?
Leonard: No. We just made out a little.
Penny: Oh, look at you, you bad boy. Did you tell her about Priya?
Leonard: Well, I was gonna, but there were too many tongues in my mouth.
& Penny: Leonard, you’re looking for a way to sleep with both women and have everybody be happy about it.
Leonard: Now we’re getting somewhere.
& Penny: What does your gut tell you?
Leonard: “Go ask Penny; she’ll know what to do.”
& Leonard: What are you doing?
Sheldon: Science. You wouldn’t understand.
& Leonard: Well... they say at the end of your life, you regret the stuff you didn’t do more than the stuff that you did, and I’m pretty sure Alice is the stuff I want to do.
Sheldon: You know, the German philosopher, Friedrich Nietzsche, believed that morality is just a fiction used by the herd of inferior human beings to hold back the few superior men.
Leonard: That actually does help.
Sheldon: It’s worth noting that he died of syphilis.
& — Who is it!
Sheldon: It’s me, Sheldon, Mrs. Wolowitz.
Howard: That’s not my mom, it’s Bernadette.
& Bernadette: Oh, my God, Howard! What did you do?
Sheldon: It was a harmless Halloween prank. Look.
Bernadette: Howard has a heart condition! You know that!
Sheldon: Well, I thought he made that up. I... Isn’t hypochondria a common idiosyncrasy of Jewish people?..
& Leonard: I... I was going to be a jackass, but I stopped myself. I stayed a good guy, so... I’m gonna pass on the sex. But you should know, that’s not a comment on your hotness but on my goodness. That’s kind of my superpower. I’m, like, Captain Good Guy.
& Priya: Leonard, relax. It’s okay. Yeah, these things happen. They happen to everybody.
Leonard: Oh, my God, you are amazing. I mean, I don’t deserve you. Wait! Wh... what do you mean “everybody”?
Priya: Leonard, I didn’t know if I should tell you, but I kind of cheated on you, too.
Leonard: Kind of?
& Priya: I guess we both messed up a little.
Leonard: No, no, I messed up a little. You messed up a lot.
& Sheldon: Bazinga, punk. Now we’re even.
--
+ quotes on Imdb.