A-List Secrets: Can That Quickie Hitchin' Last?

How long do you think Nick and Mariah will stay married?
—L.H.

Are you insinuating a less-than-robust future between a 27-year-old rapper and diva who walks her dogs in evening wear and complains when her Jack Russell can't get an airplane seat in first class? Honestly, son. Where's your faith in hip-hop humanity?

If you must know, celebrity therapists say they've seen whirlwind relationships like Nick Cannon and Mariah Carey's—plenty of times. And things rarely end well.

Click into the jump to see which insta-hitchings are still solid and who split quick.

Aside from Nick and Mariah, who are said to have dated less than two months before getting hitched, Tom Cruise and Katie Holmes got engaged less than two months after their first public outing in 2005. Renée Zellweger married Kenny Chesney about four months after meeting him.

Holmes and Cruise are still a match made in Thetanland, but Zellweger ended up separating from Cheney four months after her ceremony.

Oftentimes, relationship expert Dr. Gilda Carle says, cracks start to show in these kinds of marriages in a matter of months, or even weeks.

"Besides the external factors, the beauty, the wealth, does he know her, know her essence?" says Carle, who has counseled scads of celebrities. "He couldn't possibly. For a good solid foundation before marriage, I always say it takes at least a year."

It's also unlikely the two have endured any sort of hardship that could serve as a crucible for their relationship, she says.

"People really should go through several crises before they get married," Carle says. "Mariah is on a pedestal right now with Nick, but what happens when she wakes up with the flu, or she has morning sickness and she's vomiting? How is going to deal with this no-longer glittery, glamoury personality?"

How about buying a private plane for her dog?

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