The Big Bang Theory Season 1 Episode 4 : The Luminous Fish Effect
Sheldon is fired from his job as a physicist at the university when he insults his new boss Dr. Eric Gablehauser (Mark Harelik). His change of circumstance sends him into a downward spiral of depression which results in working on developing luminous fish for nightlights and buying a loom. Leonard tries to cure him by sending for Sheldon's mom, Mary Cooper (Laurie Metcalf). When she arrives for a visit, the men realize she is completely the opposite of what they expected: she is sweet and down-to-earth, if culturally ignorant, and a devout Christian. After waiting it out, Mary finally forces Sheldon to apologize, and he is given his job back after she flirts with Dr. Gablehauser. As Mary is a widow, Sheldon asks if Dr. Gablehauser will be his new daddy and his mother replies, "We'll see..."