Mariah Carey "upsets" people on Christmas Day because she insists on sleeping in.

Mariah Carey

Mariah Carey

The 'All I Want For Christmas Is You' singer - who has children Moroccan and Monroe, four, with ex-husband Nick Cannon and is dating billionaire James Packer - always has an elaborate celebration but admits her loved ones are less than impressed when she insists on starting her festivities late.

She said: "I love Christmas, but I am a late sleeper. I sleep in and that can make people a little upset on Christmas morning.

"So I have my friend - the real Santa Claus - come to the house in Aspen with real reindeer. This is true.

"He fills a stocking and sometimes he leaves a bag with gifts in it on Christmas Eve.

"Then, the next day the kids get the gifts. It's fun and it's festive.

"Before I had my babies I used to do this for my friends and their kids. I would invite Santa and the reindeer and he would take a video of them."

While 'All I Want For Christmas Is You' has become an essential festive song, Mariah had no idea how big the track would be when she released it in 1994.

She told HELLO! magazine: "It's so funny that people ask me about this song. I remember writing it in a little room on a little keyboard.

"I was by myself thinking, 'What are all of the things that remind me of Christmas and the holidays?'

"Of course, I wanted it to work and be a hit Christmas song but I never knew how big it would be."