The Big Bang Theory Season 2 Episode 20
The Hofstadter Isotope
Desperate to get out of the rut in their lives, the guys switch up Thursday pizza night to "Anything Goes Thursday." In addition to the crazy addition of Thai food, the guys decide to head out to the comic book store and take Penny, who needs a gift for her nephew, along. At the store, Penny meets the store owner, Stuart (Kevin Sussman). Stuart may be nerdy, but he turns out to be somewhat charming artistic. He draws a portrait of Penny which he exchanges with her for her number.
Much to Leonard's chagrin, Penny ends up going on a date with Stuart. Why does she like another nerd, who's essentially him? Being score, Leonard finally agrees to go with Wolowitz and Raj to ladies' night at a local bar. While there, Leonard and Wolowitz strike out while Raj takes home a fatty. He ends up sleeping with the woman and even enjoys cuddling the next morning. Sheldon, meanwhile, stays home and ends up crashing Penny's date with Stuart when she attempts to take him in for "coffee." They argue about comic books until Penny falls asleep leaving Stuart to go home unlucky. Do you think Sheldon did it to protect Leonard?