Craig Ferguson reveals most difficult guest on 'Late Late Show'

On "Plead the Fifth," a juicy segment on "Watch What Happens Live," Craig Ferguson revealed the 'worst' guest who was ever on his show.

The answer? Macy Gray.

"I think she was in a bad mood that night," Ferguson said. "I don't think she's a bad person. I was very new, and I couldn't handle it."

Host Andy Cohen prefaced the question by saying "Now that you're leaving ...," 'cuz it doesn't matter who Ferguson upsets since he's leaving his show in December.

And while it seems like Ferguson may have been trying to soften the blow that Gray was the worst, blog Pajiba pointed out ... "but only if Macy Gray is also in a bad mood every day of her life, because she's notoriously rude."

All right, we'll stop there, we don't want to turn this into a 'bash Macy Gray' piece. Plus, she hasn't responded on Twitter yet, so we have zero ammo to work with.

As any fan of the show knows, Ferguson is leaving his "Late Late Show" in December. He's moving to greener pastures and will be hosting the game show "Celebrity Name Game."

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