Can Leonard be friends with Penny while dating Priya? It might be a challenge.
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Who needs human companionship?!? Not Sheldon, this character hopes, on the episode titled "The Zazzy Substitution."
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Sheldon requires a chaperon on his first date when season four of The Big Bang Theory kicks off. Penny is chosen for the job.
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Poor Penny attempts to go bowling as Raj and Wolowitz watch on and drool.
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Penny and Leonard come outside to see Sheldon trapped by a net from the security system they installed.
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As usual, Leonard and Penny get into an argument. This time? About psychics.
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Sheldon helps decorate the tree and wants to add the bust of Sir Isaac Newton, which he argues is more Christmasy than Jesus.
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Penny and Leonard's mom, Beverly (Christine Baranski) go for some shots of tequila at the Cheesecake Factory.
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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.

Sheldon: If you could wake up tomorrow having gained any one quality or ability, what would it be?
Penny: Well, not to steal from the Bible, but turning water into wine sounds pretty good.