Season 2: Episode 22 - The Classified Materials Turbulance

The Classified Materials Turbulance: Stuart, played by Kevin Sussman, the comic book sales clerk goes to Leonard to ask his advice on dating Penny. Leonard advises him to act very shy around Penny. Leonard later finds out that Stuart's date with Penny goes all wrong because while making out, Penny calls out Leonard's name. In the mean time, Wolowitz has designed a toilet for the International Space Station, and has left out one of the most important parts. All the guys rally around to try to find a fix for the space toilet.