Directed by: Mark Cendrowski
Story by : Chuck Lorre & Richard Rosenstock & Steve Holland
Teleplay by : Bill Prady & Steven Molaro & Maria Ferrari
Original air date: December 7, 2009
Howard becomes jealous of Leonard after Bernadette shows an interest in his work, causing friction in the relationship of all three. Penny becomes jealous over not being able to talk to Leonard about his job, and asks Sheldon to teach her about physics.