Marriages are made in heaven, as they rather cheesily say. But are they, really? Then why do so many people cheat on their partners with men or women that may not even be half as beautiful, brainy or even buxom as their current partners – who they have promised to love, honor, and obey till death do them part? What is the lure of the other man or woman that makes these people forget their marriage vows and betray the one person that they were supposed to love with all their heart? What is so special about having sex with another person that all their vows fly out of the window in face of a little temptation?

We may never know. Or perhaps some of us already do. These unfaithful celebrities certainly do, because they are the ones who killed their marriage for a fling, or two, or in the case of one sportsperson here, 20! For the betrayed partners of these unfaithful celebrities, having their trust broken was perhaps one of the hardest pills to swallow – considering they had to face being cuckolded by their lovey-dovey spouses or special someones under media spotlight and public scrutiny.

Some of these "victims" may have been aware of their spouses’ habit for playing the field but for most, the unpleasant reality came crashing down on their heads when news of their betrayal became juicy gossip fodder. Here are the fifteen of the nastiest, unfaithful celebrities whose affairs ruined their marriages (and their lives) for good.

Two Peas In A Pod: Ryan & Reese

So Ryan Phillippe and Reese Witherspoon met at her 21^st birthday party in 1997 and the birthday girl was seemingly hooked to Phillippe’s effortless charm - she even joked that he was her birthday gift. The next year they got engaged and still the next they got married and had a daughter. In 2003, they also had a son. Life seemed idyllic for the pretty blondes except that in 2006, Reese filed for divorce, blocked Ryan from receiving spousal support, and wanted sole custody of both her kids.

While the official statement was “irreconcilable differences,” speculation remained rife that this happened because of Ryan’s increasing interest in his co-star Abbie Cornish from the movie Stop-Loss. Reese cut off ties from Ryan, cut her losses, and moved on to better things – namely, Jake Gyllenhaal (though that was short lived too). She’s been married to talent agent Jim Toth since 2011. Ryan, on the other hand, claimed to be in a deep dark place after the divorce but ironically was in a relationship with Abbie till 2010, after which he has bounced around a few times more.

Too Much Of A Swing: Tiger & Elin

Tiger Woods seemed like the perfect gentleman golfer with a gorgeous wife...that is till the Internet broke over his alleged affairs, with a capital S. As in one too many affairs. More like 20 different women. So apparently golfers are not immune to chicks who are not their wives. Unfortunately for him, Tiger erred far too many times to be forgiven.

Erin dumped his sorry sex-addicted ass, and rightfully so, after suing him for nearly all of what he was worth. Tiger Woods went on record to apologize for his indiscretions and even went to sex addiction rehab (yes, it exists) but frankly, no one will ever see him the same way ever again. Now he’s just a sorry ass man who simply could not keep his pants on, who is incidentally a great golfer.

Infidelity Is Normal, Fidelity Is So Not: Ethan & Uma

Okay, call me a traditionalist but the bumbling Ethan Hawke and the uber tall and hot Uma Thurman did not a good match make. Don’t you think so? No? Well, I guess that’s just me then. So anyway, Uma Thurman and Ethan Hawke met on the set of the film Gattaca in 1997 and needless to say, they hit it off. So much so that by the next year, they were already married. And had a daughter too. Another son followed in 2002, but again, the fairy tale crumbled and by 2005, Ethan and Uma divorced.

Though Hawke vehemently denies this, apparently the marriage crumbled due to Hawke’s propensity for the nanny Ryan Shawhughes. The unlikely pair married in 2008 and now they have two daughters as well. Mention infidelity to Hawke, and this is what he has to say: “People have such a childish view of monogamy and fidelity. He's cheated so he's bad, she's cheated so she's bad, as opposed to recognition that our species is not monogamous…” Yep. According to this philanderer, fidelity can't be the whole thing you hang your relationship on. Wonder what the other unfaithful celebrities have to say about that?

Young Love Doesn’t Last: Robert And Kristen

When Robert Pattinson and Kristen Stewart starred in the Twilight series, well, people loved to see them together. Apparently, they loved it too and were soon the most adorable “It” couple on the block. They even had their own special couple names – Robsten or KPatz. So while they were not married, they were very much together and very much in love. So when Kristen's PDA pics with director Rupert Sanders came out, suffice to say, Rob was the most shocked, with the world following at his heels.

Kristen got her ass dumped by a very hurt Rob and the world poured its hate for her cheating heart as well. Since the evidence of Kristen’s and Rupert’s make out session was undeniable, the cheating duo issued separate apologies. Needless to say, Rupert’s wife Liberty Ross filed for liberty as well, as in divorce.

Bad Boys Remain Bad: Sandra & Jesse

Sandra Bullock was in a good place when she decided to marry Monster Garage mechanic-host and all-around bad boy Jesse James in 2005. Maybe she thought that she was his redemption, maybe he was her treat – we don’t know. What we do know is that this wasn’t a match made in heaven since Jesse James had been carrying out a whole lotta affairs during their 5-year-old marriage.

Trouble brewed in 2010 when the news of the first affair hit the marriage – but Sandra put on a game face and tried to forgive Jesse for his transgression. What’s an affair or two if the love is still there, right? But when the ladies just kept on coming, Sandra had enough. She called it quits and the marriage ended in a divorce despite tearful public apologies by Jesse. The moment she dropped Jesse, the Oscars chose her, and Sandra seems to be in a happy place since.

Trouble In Cougar Town: Ashton & Demi

When Demi Moore got hitched to way younger boy toy Ashton Kutcher, cougars celebrated and mothers the world over locked their boys in their room. Yes, we are exaggerating. Anyhoo, Ashton Kutcher did “fall in love” with Demi, 16 years his senior, after dating for two years and getting married in 2005 – it seemed this was truly one romantic and everlasting love story.

No such luck. Ashton gave a rather rotten anniversary gift to Demi, because just a day before what was their sixth wedding anniversary, Aston hooked up with some random party girl. And things went downhill fast. The two divorced though Ashton seems to have fared far better Demi now that he reconnected, married, and had kids with Mila Kunis. Demi is still struggling, though we wish she’d just pull up those cougar instincts and go on a hunt again.

What’s Sauce For The Goose: Jude & Sienna

Jude Law and Sienna Miller looked so beautiful together that it pained mortal eyes. Despite the gorgeousness of the pair, their relationship has been more tumultuous than beautiful. After marrying and having three kids and divorcing Sadie Frost, Jude Law starting dating Sienna Miller in 2000. In 2004, they  got engaged, but before they could reach the wedding altar, Jude cheated on Sienna with, well you guessed it, the nanny. Really Jude, the nanny?

He frolicked with the nanny of his children with his ex-wife but even that was too bitter a pill to swallow for Sienna and the pair broke up in 2006. After a couple of hook ups, a married man for Sienna and another hookup and child for Jude, they got back together in 2009 and even spent Christmas in Barbados with three of Jude’s kids. By 2011, the split was back on, though we don’t know if a nanny was involved again!

Oh, Where Have You Been Billy Boy? Billy Bob & Laura

So Billy Bob Thornton is no stranger to marriage, or to divorce – having been married six times and divorced five times. Yep, strangely, despite his phobia of antique furniture and silverware, he still managed to keep a wife. That said, he was involved with actress Laura Dern and they became a couple in 1997, apparently very much in love and on the verge of getting married. That is until Billy Bob here starting shoot for the movie Pushing Tin, which co-starred the very hot, 20 years younger Angelina Jolie. Billy Bob then lost his head, dumped (or got dumped by Laura) and got hitched to Ms. Jolie instead in 200o.

After wearing vials of (each other's) blood around their necks and having some rather risqué tattoos too, Jolie and Thornton called it a day and divorced in 2003, having separated in 2002. So Billy Bob gathered his heart and got involved with makeup artist Connie England, and is still with her, having married her in 2014.

A Pitt Stop For The Hunk? Brad & Jennifer

Brad Pitt and Jennifer Aniston were undoubtedly Hollywood’s golden couple. After they were introduced by friends and started dating in 1998, media went nuts trying to speculate where their relationship was headed. And when they got married in 2000, well, it seemed like a fairytale happily ever after.

And then Brad Pitt started shooting for Mr. & Mrs. Smith with Angelina Jolie and all hell broke loose, at least at the Pitt-Aniston homefront. According to various media reports, a heartbroken Jennifer ordered Brad to leave their home after he confessed that he now was in love with Angelina. And despite reports of them having a physical fling as well, Jennifer chose to believe her ex-husband who said that there was no intimacy of the body, just of the heart and mind. It took Jennifer years to get over her marriage to Brad, which she still mentions as a special time, but she is now happily married to Justin Theroux. As far as the new Mr. & Mrs. Smith, er, Pitt – we all know how that boat sank now, don’t we!

Mad Max Revisited: Mel & Robyn (And Mel & Oksana)

So struggling actor Mel Gibson met dental nurse Robyn Moore, and just like that, they were married in 1980, way before Mel became one of the Hollywood biggies. After one daughter and six sons (wow Robyn), Mel had his famous Oksana Grigorieva incident. Basically, Mel threw away 26 years of marriage for a torrid affair that ended with Robyn Gibson filing for divorce, and Mel getting into a relationship with Oksana.

While Mel and Robyn’s marriage ended on a gracious note, or at least on a publicly gracious note, the same cannot be said about the end of Mel and Oksana’s relationship. Both parties took out restraining orders against each other (despite a child they had together), and Oksana ended up with a pittance of a settlement, unlike Robyn who took a huge $400 million chunk! Mel is now involved with yet another nubile youngling who gave birth Mel’s ninth child. Mel, who do you think you are, Father Christmas?

Movies 10, Marriage 0: James & Linda

James Cameron sure knows how to make movies. But one thing that he doesn’t know how to do, is to make his marriages...work, that is. He has been churning out hit after hit for so many years, that we’ve basically lost count. What James Cameron doesn’t know how to do, according to his ex-wife Linda Hamilton (remember the original Sarah in the original Terminator with the original Arnold?), is to stay faithful to his marriage vows.

Five-time married James was married to his fourth wife Linda Hamilton in 1997. Barely a few months later, James was making Titanic which also starred Suzy Amis (who plays Rose’s granddaughter) and they embarked in a sneaky hooky session. Linda found out and divorced Cameron’s sorry ass in 1998. James and Suzy married in 2000 and James finally seems to have settled in matrimonial bliss. Is fifth time a charm James?

I Dumped You But Kept Your Name: Ashley & Cheryl

Cheryl Ann Tweedy was a rising star in music as she rose to fame as a member of the band Girls Aloud. She met footballer Ashley Cole in 2004 and the couple soon fell in sweet love. After dating for two years they got married in 2006 in a fairytale wedding. Things seemed to be all right for a while but in 2010, Cheryl filed for divorce. The reason? Well, Ashley could not keep it in his pants and had been cheating on Cheryl with just about any woman he could find.

When Cheryl found out about Ashley’s wandering eye, she was devastated and admitted that for a while she felt very, very depressed. The fact remains that Ashley Cole cheated on Cheryl for no fault of hers and in doing so treated her badly. Cheryl dumped Ashley but let’s face it, Cole was a definite improvement over Tweedy! Now Cheryl is involved with Liam Payne, and they also have a son together. Ashley is still philandering when we last checked.

Proof of Cheating? Meg & Dennis

Between the late 80s and the early 90s, Meg Ryan and Dennis Quaid acted in some three movies together and got into a relationship too. When Meg asked Dennis to stop using cocaine before they got married, he agreed and so they got married in 1991. For the next nine years or so, they seemed to be totally in love and seemed to be in a rare, successful Hollywood marriage.

And then Meg Ryan began to shoot the movie Proof of Life with Russell Crowe. While Meg Ryan was still married to Dennis, she and Russell began “dating.” Dennis was completely blindsided by this and when this affair became public knowledge, the world sided with Dennis. Meg slipped down a few notches in public opinion and so did Russell. Later, Meg also said that Dennis had been unfaithful to her as well but by then it was too little, too late.

When Terminator Wasn’t Wanted Back: Arnold & Maria

So, Arnold Schwarzenegger was a mega-bodied, mega-popular, mega-rich mega actor. To top that off, he is now a politician. Does that mean that he was “pre-programmed” to stray from his wife? Some would agree.

Whatever your opinion is, when Arnold got married to Maria Shriver from the Kennedy family, it just seemed like the American Dream coming true considering he effectively married American royalty. And to give them both credit, the marriage did last for 25 good years. In 2011, Maria confronted Arnold about the teenage child of a housekeeper who seemed to look a lot like him. While Arnold had lied by omission, this time he didn’t and accepted that he had fathered this child with their Guatemalan housekeeper, around the time she herself was pregnant with their youngest son. Maria Shriver had had enough and so she walked and their marriage came to a court-settled end. Later, actress Brigette Neilsen (remember Red Sonja?) also admitted to having an affair with Arnold while he was married to Maria, making the Terminator one unfaithful celebrity.

Nannygate Revisited: Ben & Jennifer

Ben Affleck and JLo made for a rather unusual pair but people were starting to see them as a couple. Before they could get married, JLo vamoosed and got hitched to Marc Anthony instead, though this gravy train did not last either.

It was then that Ben found another Jen, Jennifer Garner, and they became a couple in 2004. The world lapped up the sweethearts, dimples and all, and in 2006, Bennifer 2.0 got married in a private ceremony. Three children, 12 years, and a nanny later, it was all over. Jennifer filed for divorce citing irreconcilable differences. Ben had erred with the nanny, though at the time Jen and he were "separated." When the news broke out, Jen had to explain to their three kids what a “scandal” meant! We found a disgruntled fan’s comment worth sharing: “You have to be special kind of stupid to cheat on Jen…” We second that!