It's pretty darn clear at this point Howard Stern is not a fan of Jay Leno, but he really ripped into the late-night talk show host on David Letterman Thursday night, making Dave visibly nervous and uncomfortable.

Stern launched into a Leno tirade, expressing:

    "Jay is horrible, right? I didn't like Jay, I never liked Jay, I can't stand Jay. I've never seen anybody who behaves like a robot like this guy. I watched his final show (when he says goodbye to the "Tonight Show") he's reading off a teleprompter for crying out loud. Where's the emotion and where's the humanity?"


The Private Parts star has good reason to remain a loyal Letterman guest; the late night host gave him a major break by inviting Stern on the show when he was relatively unknown.

In other news, Leno will be in Massachusetts Friday night, to receive Harvard's Hasty Pudding 2011 Man of the Year prize. Wonder what Stern's going to say about that one?

Find out how two lesbians started the feud between Leno and Stern, after the jump!