You're looking at a scene from The Infestation Hypothesis. It's episode two of season five.
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Leonard confronts Penny in this scene from the season five premiere of The Big Bang Theory. She sure finds something funny!
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The gang is all here. And we mean everyone! Check out this scene from the fifth season premiere of The Big Bang Theory.
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This is awkward for everyone. Raj and Penny stand in front of the boys on the fifth season premiere.
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Sheldon takes charge of the paintball team on the season five opener. Is this really a good idea?
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We all know what happened between Penny and Raj on the season four finale. Here they are on the ssason five premiere.
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Amy has so many questions for Penny on the season five premiere. They are all based on sleeping with Raj.
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Bernadette reacts to the news here. Yes, Raj did Penny!
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TBBT Quotes

Sheldon: Why do you have the Chinese character for "soup" tattooed on your right buttock?
Penny: It's not "soup," it's "courage."
Sheldon: No it isn't. But I suppose it does take courage to demonstrate that kind of commitment to soup.
Penny: How'd you see it? You said you wouldn't look.
Sheldon: Sorry. As I told you, the hero always peeks.

Sheldon: Nothing more fun than a paradigm shifting evening of science.
Penny: (to Leonard) And you thought it was soaping me up in the shower.