Mary Cooper: So who else is coming to this shindig?
Amy: Oh, well, the usual gang. Penny's family is coming tomorrow.
Sheldon: Yeah, and Leonards mother's already here.
Mary Cooper: Oh. Beverly. How nice.
Amy: You've met her, right?
Mary Cooper: Yes, I have. (reveals her cross necklace)
Sheldon: Mother, she's an atheist, not a vampire.
Mary Cooper: Either way, let's stop and get some garlic.