Leonard comes home to find out the guys spied on how his date with Penny went via a webcam they put in the hallway.
Penny tells poor Sheldon a secret whether he wants to hear it or not. Unfortunately that secret involves Leonard and puts him in a difficult situation.
Penny and Leonard return from their first date and Penny tells Leonard she wants to take it slow. Poor guy.

The Big Bang Theory Season 2 Episode 1 Quotes

Leonard: [Sheldon] says he's moving out.
Raj: What did you do? Did you change the contrast or brightness settings on the television?
Leonard: No.
Raj: Did you take a Band-Aid off in front of him?
Leonard: No.
Wolowitz: Did you buy generic ketchup? Forget to rinse the sink? Talk to him through the bathroom door?

Penny: Has [Leonard] ever been involved with someone who wasn't a brainiac?
Sheldon: Oh, well, a few years ago, he did go out with someone who had a Ph.D. in French Literature.
Penny: How is that not a brainiac?
Sheldon: Well, for one thing, she was French. For another, it was literature