During Stern's appearance on Monday's The Late Show, he revealed to the audience that Letterman had invited the night's other guest, legendary comic Don Rickles, out to dinner, but hadn't invited Stern.
"Do you think I was invited? I wasn't invited. Terrible!" Stern said, standing in front of his desk. Before Letterman could defend himself, Stern asked the host to follow him to the middle of the stage.
Nervously, Letterman walked into the spotlight with Stern, who began to grab Letterman's jacket lapels.
"What are you gonna do?" Letterman asked, trying to back away.
"Come here and hug me," Stern said, pulling the host in close. They held their embrace for a moment before Stern went in for the lip lock.
"Kiss me!" Stern yelled over Letterman's cries of dismay.
It might have been slightly awkward, but it was also super adorable. Two good friends saying their goodbyes in the insane manner you'd expect from the two legendary hosts.