Regis Philbin tries to kiss David Letterman before his last day at 'Live'

Regis Philbin and David Letterman are close. Very close. So close, in fact, that the pair almost shared yet another kiss when the talk show host visited the "Late Show" Thursday night (Nov. 17). Huh?

Here's what happened: Letterman stopped by "Live! With Regis and Kelly" in advance of Reege's Nov. 18 exit, and the two shared a tender moment. "The man got up out of his seat, and he was excited," Philbin tells the "Late Show" audience of their encounter. "And we were all excited because you don't see him anywhere, so the man approached me, and I'm thinking, 'Where's he going with this?'" 

Well, he went in for a kiss! "Suddenly it was this, thank you very much," Reege says. "On the lips! On the lips!"

Letterman, clearly charmed by their encounter, says, "I enjoyed every second of it. I'd do it again in a heartbeat."

But it seems Dave doesn't hold up his end of the bargain. Philbin tries to get another kiss out of Letterman, asking, "Why can't we have one more, one more just for the road?"

No kiss. "You're a slut," Letterman replies. "That's what you are."

Ever the comedian, Philbin replies, "Well, you're turning me into a slut."