Nick Cannon is rumored to be staunchly opposed to the idea of soon-to-be-ex-wife Mariah Carey taking their twin 4-year-olds to Australia to meet the family of new billionaire boyfriend James Packer.

According to OK magazine, "The America's Got talent" star has no plans of allowing his children to make the trip and has made Carey aware of that in no uncertain terms.

"He's always been worried about Mariah drinking around the children, and I'm sure he will use that to his advantage," a source added. "There is no chance those kids will be leaving the country."

Since officially becoming an item earlier this summer, Carey and Packer have been rumored to be on fast-track in their relationship to the point of reportedly already contemplating marriage.

OK magazine reports the billionaire Australian businessman has allegedly proposed to the "Hero" singer and promised to buy her "a large estate on the island of Capri, Italy" once their nuptials have been made official.

''He's planning on buying out a large section of Capri -- her favorite place in the world -- for a sky's-the-limit wedding,'' a source said.

Carey, 45, and Packer recently spent Fourth of July weekend together in Las Vegas after jetting back from an extended stay on his king-sized yacht in the Mediterranean.

Several media outlets have also reported the couple ventured to Israel during their extended vacation for a "pre-engagement spiritual meeting" with Packer's longtime religious adviser.

Carey and Cannon were married for six years before he recently filed for divorce. She has also been married to record label executive Tommy Mottola. As for a Packer, a source added, ''Mariah is having a lot of fun being courted. It's very different than when Nick Cannon was wooing her. To her, Nick was a boy. James is a man."

Since his split from Carey, 34-year-old Cannon has been romantically linked to Sports Illustrated swimsuit model Jessica White, entertainer Amber Rose and Eddie Murphy's ex-wife Nicole Murphy.