Leonard: You told her I lied? Why would you tell her I lied?
Sheldon: To help you.
Leonard: I'm sorry, I'm not seeing the help.
Sheldon: She was going to see through your lie eventually, so I told her that you were lying to protect me.
Leonard: Oh, I'm getting a bad feeling.
Sheldon: Hunger? Indigestion? I'm sorry. I'm really not very good at this.