Sheldon Calls Zack to Satisfy Horny Amy | The Big Bang Theory

Sheldon talks to Penny about this relationship with Amy which he thought was a purely intellectual one. She has changed and had become a slave to her baser urges... like Penny. Penny tells him that he can help her with those urges. Instead of going to satisfy Amy himself, he decides to get Zack to do it.

Season 04 Episode 10 - The Alien Parasite Hypothesis