David Letterman was having so much fun with his favorite actress, Larry Crowne‘s Julia Roberts, that he seemed peeved that the audience was in the room. When they interrupted his conversation about children with a half-sincere, “Awwwwww,” he fired them the double-bird. No feelings were hurt, fortunately. Take a look.
Reminds me of another classic bird-bit from back in the day. Though it only qualifies as offensive if you're upside-down. Hilarious, no matter how you're standing.