The 'America's Got Talent' host - who married the 'Hero' hitmaker in 2008 ' tries to romantically sing his wife's own songs to her but always ends up ruining them.

When asked if he ever sings to Mariah, Nick answered: 'Absolutely, and I am the worst singer ever and I try to serenade her with her own songs and I mess up all the words and she just laughs.'

The TV presenter also spoke about the vacancy for judges on 'American Idol' - following the departures of Simon Cowell, Ellen Degeneres and Kara DioGuardi - and he thinks Mariah would be perfect for a spot on the panel of the pop star search show.

He added to US TV show 'Extra': 'She's a voice technician, people don't really understand how her vocal chords work and how hard she actually works at it, so a show like that would give her a great opportunity to show people what it really takes to be one of the world's best singers."

Nick, 29, previously revealed the 40-year-old singer often speaks about judging hopefuls on the series.

He said: "You know what? She talks about it. She says, 'I would love to do that.'

"She is one of the greatest singers of our time; she would be great. I don't know if she has enough time, though, but if they could work with her schedule, I know she would love to do 'American Idol'."