Penny: Uh, what's new?
Zack: Oh, tons of stuff. Put artificial grass in my backyard, got engaged, had a scary mole that turned out to be Sharpie.
Penny: Well, congratulations.
Zack: That's what my dermatologist said.
Penny: No, on getting engaged, good for you.
Zack: Oh, thanks.

Zack: One question. How can you be sure it won't blow up?
Leonard: The laser?
Zack: The moon.

Leonard: Don't worry about the moon. We, we set our laser to stun.
Zack: Smart.
Leonard: Now, we'll be able to see the beam when it leaves, but it won't be strong enough when it comes back to be seen by the naked eye.
Zack: (chuckling) Naked.

Sheldon: Jacuzzi is a commercial brand, hot tub is the generic term, i.e., all Jacuzzis are hot tubs, but not all hot tubs are Jacuzzis.
Zack: Is that like all thumbs are fingers but not all fingers are thumbs?
Sheldon: Surprisingly, yes.
Zack: Nice! Now what exactly are toes?

Sheldon: Physicist, baker, lover, what can't I do?

Penny: I didn't know you could drink while you were breastfeeding.
Bernadette: Yeah, they say the yeast in beer helps with milk production.
Amy: I'm pretty sure that's a myth. Let me check.
Bernadette: Ruin it for me, and I'll break this glass over your head.

Penny: You want food?
Bernadette: Yeah, breastfeeding burns, like, 5,000 calories a day. (To Amy) Do not touch that phone!