02/02/2012 11:01 am ET

Howard Stern Tells Letterman He Won't Go On Leno To Promote 'America's Got Talent' (VIDEO)

For David Letterman's 30th anniversary show celebrating three decades on late night television, he invited one of his favorite guests, Howard Stern, to "The Late Show." While there, Stern confirmed his loyalty to Letterman by telling the host that despite working for NBC as a judge on "America's Got Talent," he refuses to go on "The Tonight Show with Jay Leno" to promote the show.

He described meeting with NBC executives about promoting the show. "They sat down and said, you'll do 'The Today Show,' and of course you'll do Jay Leno," Stern told Letterman. "And I shot them a look and said, 'You know I'm a Letterman guy.'"

Of course, the feud goes back two decades, when Letterman felt that he had been passed over for the "Tonight Show" job upon Johnny Carson's retirement in favor of his friend Leno. In 2010, history repeated itself when Conan O'Brien took over "The Tonight Show," before NBC decided to give the show back to Leno after seven months. Throughout the ordeal, Letterman gleefully mocked Leno on the air for several weeks.

Stern has made his distaste for Leno clear over the years. When O'Brien was first announced as the "Tonight Show" host, Stern made an appearance on "Late Night" where he predicted that Leno would try to take back the show.

Many were shocked when Letterman called a "truce" with Leno last month.

Turns out, Letterman's heart may not have been in it. He told Stern last night that he called the truce because he had said some nasty things on the air about Leno lately, and wanted to backpedal. To boot: "If Jay Leno wins the People's Choice Award, it'd be like hearing that Manson has been paroled."

In 2011, Letterman beat Leno in the ratings for the 18-49 demographic for the first time since 1994.