I'm sure you heard about the big dust-up on CNN last week when Joan Rivers walked out during a live interview when she felt the interviewer was getting "very judgmental and nasty". Rivers was trying to promote her new book when, instead of the book, the focus turned to her and some of the comments she's made recently regarding President Obama and his wife and other celebrities.

During a visit with David Letterman, she explained it's all in fun....It's comedy, trying to make people laugh, and that's what the book is all about. That's when Letterman turned the tables and walked out on her.

It's all in fun, of course, but really funny. He gets up  and walks away at about the 4-minute mark, leaving Joan on the set by herself, so she just starts interviewing herself.

Warning: If you're offended by rough language, you may want to move along to something else.