Lionel Richie has called King Charles a "secret comedian".
The 'All Night Long' legend managed to convince the newly crowned king to appear on 'American Idol' with Queen Camilla last week, and he admitted it was actually very much in "his comfort zone".
He told Extra: "I've known the King quite a long time. He does have this amazing sense of humor that no one knows about.
"He's a secret comedian... For him to actually take the step and go out of the comfort zone — which was actually his comfort zone — he was hamming it up."
The 73-year-old star revealed the surprise appearance came together relatively easily after the recent Coronation.
He said: "The highlight for me was that I actually walked up to the King the day after the coronation and said, 'Would you like to be on American Idol and he said, 'Yeah.'
"And the second thing that was the highlight was he said, 'Alright if I bring the Queen?' 'Uh, yeah.' "
He hailed the king and queen, 74 and 75 respectively, as an "amazing couple", pointing to their work with the Prince's Trust.
Lionel was named the charity's First Global Ambassador and First Chairman of the Global Ambassador Group in 2019.
he added: "They are an amazing couple. On top of that, they are putting so much good out in the world with the Prince's Trust."
They joined Lionel and Katy Perry - who also performed at the Coronation Concert - on 'American Idol' on the May 7 launch episode.
Last month, the star revealed how much an invite to the Coronation - and the chance to perform 'Easy' and 'All Night Long' - meant to him.
He told PEOPLE magazine: "I mean, you don't get in the business and say, 'You know what? I'll be at the King's coronation.' You know, that just never comes up.
"[It's] A, a surprise. B, what an honor. And C, the fact of all the names that are out there that he could have had for this, he called my name."
Tagged in Katy Perry Lionel Richie King Charles