As usual, Leonard and Penny get into an argument. This time? About psychics.
Sheldon helps decorate the tree and wants to add the bust of Sir Isaac Newton, which he argues is more Christmasy than Jesus.
After years of trying to get his mother's affection, Leonard finally gets a hug from Beverly (Christine Baranski). All it took was getting her drunk.
Bernadette (Melissa Rauch) joins the guys for lunch at work as she begins to bond with Leonard over his work.
Wolowitz confronts Leonard when he gets jealous over his friend bonding with his girlfriend, Bernadette.
When Sheldon is embarrassed by Kripke on National Public Radio, Sheldon comes to comfort his friend.
Raj attempts to scare the guys with a ghost story but they look a little more bored than scared.
Leonard, Raj and Wolowitz are definitely not the manliest of men. Here they are a little scared on their camping trip.

TBBT Quotes

Penny: Here's a question-- as an alien pretending to be human, are you planning to engage in any post-prom mating rituals with Amy?
Sheldon: There are post-prom mating rituals?
Penny: Not always. Unless your date drives a van with an air mattress, then always.
Sheldon: Well, if it's part of the prom experience, then I'm open to it.
Penny: You're kidding.
Sheldon: I may be an alien, but I have urges.If Amy wants to copulate by firing her eggs into space, well, then, I will happily catch them with the reproductive sac on my upper flermin. I'm not the best at reading facial cues, but I can see that you're a little turned on.

Raj: Well, to paraphrase Shakespeare: It's better to have loved and lost than to stay home every night and download increasingly shameful pornography.
Penny: Oh... you poor baby.
Raj: What's wrong with me, Penny?
Penny: Nothing, nothing. You know, if we weren't friends - and you hadn't brought up that creepy pornography story - I'd be on you like the speed of light squared on matter to make energy.
Raj: Hey, you totally got that right. E = MC squared.
Penny: I listen. I have no idea what it means, but I listen.