Letterman: 'I'm making fun of Jay Leno relentlessly, mercilessly, because I'm really enjoying it.'

David Letterman, responding to a report in The New York Times that quoted NBC executive Dick Ebersol as calling him and ousted "Tonight Show" host Conan O'Brien "chicken-hearted and gutless" in their jokes about Jay Leno, the "Late Show" host told his CBS audience Monday night that Ebersol, a long-time sports executive at NBC, should spend less time weighing in on late night and more time picking out Bob Costas' sweaters and scarves for the upcoming winter Olympics. Letterman told a cheering audience, "I'm telling jokes and making fun of Jay Leno, over and over and over, relentlessly, mercilessly, simple for one reason and that is -- I'm really enjoying it. I don't know, it's just fun!"

Letterman, who has taken to referring to Leno as "Big Jaw," has been gleefully enjoying NBC's disastrous "Tonight Show" debacle, weighing in with the kind of stinging barbs (most of them directed at NBC chief Jeff Zucker and Leno) he was famous for directing at the peacock network in the 1990s, when NBC chose Leno over Letterman to fill Johnny Carson's chair. The then "Late Night" host bolted to CBS and created one of the first enduring franchises to effectively compete against "Tonight." On his way out, he took every shot imaginable at NBC, even calling out virtually anonymous executives by name, showing their pictures on the air and mercilessly making fun of them. Letterman rarely, if ever, took shots at Leno during that time and over the years, he has only mentioned Leno sporadically (and mostly positively) until now.

The two men have often characterized their relationship differently in public. For some time, Leno has maintained that the two are friends and have been since their stand-up comic days in Los Angeles, but Letterman told Rolling Stone in 1993, "I speak to Jay now with the same regularity that I have always spoken to Jay. Which is not much. There is no ill will personally." Given Letterman's notorious anti-social behavior, that might actually constitute a friendship. At any rate, the two did have some nice on-screen chemistry when Leno appeared on Letterman's old NBC show.