Penny: No, what I'm saying is you could add a clause to the contract that he can't make fun of Howard.
Bernadette: How would you enforce it?
Sheldon: Oh, please. Any contract I sign is enforced by my own personal code of ethics.
Amy: And his obsessive-compulsive disorder.
Sheldon: Yeah, that, too. And scoot over. Part of your shadow's on my spot.