Alec Baldwin Gets Rude and Thoughtless on ‘Letterman’ (Video)

“30 Rock” star disses his former Oscars co-host from the peanut gallery

Alec Baldwin made an appearance on Wednesday night's "Late Show With David Letterman" — but this time it was from the audience, not on the stage.

The "30 Rock" star put the brakes on Letterman's monologue and expressed his distaste for guest Steve Martin, walking out on the show and declaring, "I'm not really a fan." Bad blood from their Oscars co-hosting gig, perhaps? Decide for yourself after watching the video.