Video: What goes around, comes around: David Letterman walks out on Joan Rivers

David Letterman turned Joan Rivers' CNN interview walkout into a great Late Show comedy moment. The late night host walked out on Joan while the two were chatting on the CBS show. (Letterman bailed when his guest started going on about adult diapers.) Unlike Joan's CNN exit, this storm out was all in good fun.

Check out hilarious clip below for your viewing pleasure.