Mariah Carey: Oh please, I haven't moved in with my boyfriend!

Mariah Carey is insistent she has yet to move in with her billionaire boyfriend James Packer.

The 45-year-old Grammy-winning singer has been dating the Australian mogul since the summer (15) and earlier this month (Nov15) TMZ reported the pair took its relationship to the next level by deciding to reside in his Beverly Hills home.

However, Mariah claims rumours they have moved in with each other couldn't be further from the truth.

"Oh, my God, I was staying at his house," she told Extra. "He wasn't there. He has houses at, like, a lot of different houses… OK? I'm sorry. I can't help it. The man owns some real estate. He wasn't there."

Mariah shares fraternal twins Moroccan and Monroe with estranged Nick Cannon, who she separated from in 2014 after six years of marriage.

When asked to use one word to describe how she is feeling right now Mariah stated "grandtastic" and the singer is happy to report her family is in the same mood despite the divorce.

"They're good," she said of the twins. "They're growing. They're four."

Mariah has a busy holiday season lined up and next week she is due to perform at the annual Macy's Thanksgiving Day Parade in New York City, a traditional celebration launched in 1924.

Although she is grateful to be participating in the time-honoured event, Mariah admits the thought of being on a parade float for several hours is somewhat daunting.

"It's gonna be fun, but I hear I'm gonna be on the float for, like, three hours… That's a long time," she noted.

She'll still be able to make it home for Thanksgiving dinner with the family, revealing her "father's recipe for linguine with white clam sauce" is a dish she can't wait to sample.

Mariah is also already thinking about Christmas, especially in light of her new children's book All I Want for Christmas Is You, a title based on her classic 1994 holiday song of the same name.

"It's about a little girl and she gets a puppy and it's so cute… It's for kids," she said of the tome.

Mariah's book All I Want for Christmas is You is currently available for sale in stores. The 2015 Macy's Thanksgiving Day Parade will also feature performances by Jordin Sparks, Panic! At the Disco, Jennifer Nettles and Trey Songz.