I've always been fascinated with the concept of marriage in Hollywood. I get that it's a different world, and people marry for different reasons exposure, money, fame or even to prove they're not gay, which is a bit bizarre when you think about it.

Sure, back in the 1930s, when Cary Grant shared a house with Randolph Scott, the notion that he might be gay would have had a major impact on his heartthrob status in the film industry.

But does it really matter in these modern times? I'll leave that for another pop-ed, but let's just ruminate on it for now.

There are plenty of celebrity marriages that probably should have been over a long time ago, but continue to thrive in an industry where if a marriage lasts a year, you're bucking the odds. Melanie Griffith and Antonio Banderas spring to mind. She was married to Don Johnson (twice) and Steven Bauer before marrying Banderas in 1996. His previous marriage lasted nine years.

So, what makes it work?

For one thing, Banderas just seems like a really good guy who can weather the storms of life. He supported her through her 2009 stint in rehab, and the couple seems stronger than ever. "There were people who literally didn't give us more than six months," Banderas said earlier this year. "But we love each other, and above all, we love our family. We've figured out how to get past obstacles ... and if you get past those, you only get stronger."

Still, it's easy to see why celebrity marriages have such a high divorce and cheating rate. Aside from the stresses of living a life where the paparazzi dog you 24/7, there are gorgeous people throwing themselves at you constantly. You have to be a very, very strong person to resist that temptation day after day.

"Being a celebrity in a monogamous marriage is like being a dieter who lives in a bakery," says Alisa Bowman, author of the upcoming book 'Project: Happily Ever After.' "The dieter is trying to live on salads, but she's surrounded by eclairs and cheesecake and profiteroles all day long. Beautiful women throw themselves at celebrity men multiple times a day. Rock stars, sports stars and actors have sexy women flashing them and offering sex at every turn. The rest of us might have the random person interested in us every so often, but that random person usually isn't quite so yummy looking as the types of random people who throw themselves at celebs."

So how do they resist the temptation? Maybe they grow out of it and realize there's something beyond one-night stands and serial dating. Warren Beatty was the biggest playboy around, but he seems to have figured it out. In a 2007 story in The Independent, he said of his 18-year marriage to Annette Bening, "She has a great capacity to be happy, which is a great gift to me and an even greater gift to her children ... For me, the highest level of sexual excitement is in a monogamous relationship. I would hate myself if I failed to live up to it."

Bowman adds that every marriage takes work, but a successful celebrity marriage takes even more of it. "I think what you'll find in common with most of the long-term celebrity marriages is that neither partner was a spotlight hog. Sure, they were famous, but they weren't the types of people who were plastered across Star magazine every single week. That keeps some of the stress off the marriage, as well as some of the temptation, too."

Seal and Heidi KlumAnd there's a lot to be said for communicating with each other and putting a high priority on the marriage. Heidi Klum and Seal renew their vows every year, and in a 2007 story, shared five rules they live by: 1) Find common ground; 2) Seize the moment; 3) Two words: commitment and respect; 4) Embrace both the big and the small gesture; and 5) Put each other first, even before the kids.

This story wouldn't be complete if I didn't mention Ron Howard, who has been happily married to his high school sweetheart Cheryl since 1975. Do the math -- that's 35 years! Will Smith and Jada Pinkett Smith declare their love publicly at every opportunity. And Betty White says she and Allen Ludden were partners in every sense of the word. "Allen and I had worked together on and off during almost 18 years of marriage, but in our private life, we were always very much a team. As well as lovers, we were each others' critic, editor, fan and friend."

When I interviewed Michael McKean a couple of years ago, the star of 'This is Spinal Tap' talked about how he and wife Annette O'Toole were nominated for an Academy Award for co-writing the song 'A Kiss at the End of the Rainbow,' featured in 'A Mighty Wind.' It was an homage to their own love story.

"We weren't separated by anything enormous, except for the fact that we weren't together for a big chunk of our lives," said McKean. "We knew each other in passing because we had a lot of friends in common. And then 10 years ago, we found ourselves both free of other entanglements, and we fell in love. Everything else fell in line. I guess the Beatles were right – all you need is love."