Lionel Richie's grandchildren didn't know he's famous!

Lionel Richie has revealed that his two grandchildren had no idea about he was a superstar until recently.

The 'Dancing on the Ceiling' singer explained that his granddaughter Harlow, 4, and 2-year-old grandson Sparrow had never seen their grandfather on stage until he duetted with their father Joel Madden on Australian TV on Sunday.

'While we were singing, I could see [daughter] Nicole with Harlow and Sparrow out of the corner of my eye, and it dawned on me they have never seen me on stage before,' explained Lionel to Courier-Mail.'

'You just know they were thinking, "What's Pop-pops doing with Dada?"'

Richie and Madden performed a rendition of 'Easy', one of Richie's biggest hits with his former band Commodores, and Lionel admits he would have been nervous had the tables been turned.

'Singing with your father-in-law is enough to make you nervous,' joked the 62-year-old. 'I would have passed out.

'It could go all wrong. But it was great.'

Lionel Richie and Friends in Concert

Confused child

Can YOU Solve The Maths Equation That's Gone Viral?

Peaky Blinders Series 4

This Exciting Teaser Is Making Us So Excited For Series 4 Of Peaky Blinders

Ant McPartlin and Lisa Armstrong

Ant McPartlin's Wife Is Still Devastated He 'Put Her Through Hell'

Contestant Ridiculed For Answer On The Chase

The Chase Viewers Have Ridiculed A Poor Contestant For This Silly Answer