The Luminous Fish Effect
The Big Bang Theory Season 1 Episode 4 (10/15/07)
Sheldon is fired from his job at Caltech when he insults his boss Dr. Eric Gablehauser (Mark Harelik). Unemployed, Sheldon quickly spirals into depressions which Leonard tries to end by bringing over Sheldon's mother (Laurie Metcalf).
When his mother arrives, she turns out to be the complete opposite of Sheldon, a sweet, devout Christian woman. Sheldon's mom forces him to apologize and he gets his job back. His mom also flirts with Dr. Gablehauser and Sheldon asks if he's going to be his new Daddy. His mom says "we'll see."