Season 1 Episode 10: The Loobenfeld Decay

 Season 1 Episode 10: The Loobenfeld Decay

Season 1 Episode 10 "The Loobenfeld Decay" aired 3/24/2008. Leonard and Sheldon each lie to avoid hearing Penny sing. Sheldon's lie becomes a bit too complicated. DJ Qualls as Toby Loobenfeld.

Penny, Leonard and "Sheldon's cousin"

 Penny and "Sheldon's cousin"

"Sheldon's cousin" and Sheldon Cooper

 Raj, Howard, Penny and Leonard