Conan O’Brien isn’t one for keeping a secret — for too long, that is.

During a performance of Watch What Happens Live, the late night host played “Plead the Fifth” and Andy Cohen asked him who his worst guest was.

“I don’t wanna plead the fifth on anything. Al Roker. The guy…it’s too fake. He’s too happy all the time,” he said. “And I kept trying to crack him. I said, ‘Al, you can talk to me.’ And he wouldn’t do it! And he goes home at night and cries. It’s Roker, I tell ya. It’s Roker.”

He later added that Al was a huge diva: “Absolute monster behind the scenes. Compensating for his own insecurities. And I haven’t spoken to him since! Your turn.”

Andy later responded with his worst guest:

“Mine is Mariah Carey,” he said, “and I think it’s a good thing. I mean, look, she had me switch seats because she has a better side. She was a diva in the way that I would want her to be a diva.”