Chris Martin's song for Mariah's boobs

Chris Martin stunned fans by singing an impromptu tribute - to MariahCarey's boobs.

The Coldplay frontman made up the song after a US reporter asked him if he thought the curvy diva was "on his tail"in the race to have 2005'sbest-selling album.

The star, who was giving a private concert for winners of a US radio contest, joked: "She's not, but one of her boobs is. They do most of her work. Last week I was chased down the street by an enormous boob. I think itwas hers."

Martin, who is married to actress Gwyneth Paltrow, then started singing: "Mariah Carey's boobs are so nice, and she doesn't mess around. If she hadbeen aboard the titanic, there's no way that ship would have gone down."

Last month, it was revealed sexy Mariah is terrified of losing her curves.

The singer said although she likes working out she can't exercise too muchin case she loses her ample butt.

She said: "I've been working out like mad - you can even punch me in thestomach and feel how tight that is.

"But I've gotta slow it down because the other day someone told me I waslosing my ass - and I don't want to lose that."