Robert Pattinson has yet to comment on damning photos of his girlfriend, Kristen Stewart, making out with her "Snow White and the Huntsman" director Rupert Sanders, but he has expressed his thoughts about cheaters before.

Us Weekly reports that the 26-year-old "Twilight" star made some interesting comments about the nature of infidelity.

In the April issue of Italian Vanity Fair, Pattinson was asked if he could ever date a married woman, and told the magazine, "Life is not black and white. There are married couples that never see each other. Is that marriage?"

Though he admits things are never as simple as they might seem, he added quite tellingly, "But there's a thing I've never got: That is, why do people cheat? I can understand the impulse, but not how you can keep two relationships going at the same time for long."

Although Pattinson recently denied that he and Stewart had plans to tie the knot anytime soon, Us Weekly claims that before news of Stewart's cheating broke, he was preparing to pop the question.

If Pattinson didn't already know Stewart had strayed from their relationship he must be reeling, as he also told Vanity Fair that he completely invests himself in his relationships.

"I'm not the casual-affair kind of guy. If I choose to be with someone, it's because I really want it. When I have a relationship, I'm 100 percent into it," he told the magazine.

That probably makes it even harder for him to learn that Stewart's affair with Sanders, who is married with two children, was reportedly "just a fling and not serious."

The photos of Stewart and Sanders together made it hard for her to deny the affair, and on Wednesday, the 22-year-old issued an apology:

"I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected. This momentary indiscretion has jeopardized the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I'm so sorry."

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  • Angelina Jolie

    In 2004, Brad Pitt allegedly fell for his <a href="http://www.usmagazine.com/celebrity-news/news/what-jennifer-aniston-thinks-of-brad-pitt-angelina-jolies-engagement-2012264#ixzz1wrQN7P9U" target="_hplink">"Mr. and Mrs. Smith" co-star, Angelina Jolie</a>, while he was still married to Jennifer Aniston. A media frenzy ensued, and soon after <a href="http://www.people.com/people/article/0,,1042412,00.html" target="_hplink">filing to divorce Pitt</a> in March 2005, Aniston opened up about the split, as well as Jolie and Pitt's <a href="http://www.wmagazine.com/celebrities/archive/brad_pitt_angelina_jolie#slide=1" target="_hplink">photo shoot as a married couple in <em>W</em> magazine</a>. "<a href="http://today.msnbc.msn.com/id/8797298/ns/today-entertainment/t/aniston-says-pitt-missing-sensitivity-chip/" target="_hplink">There's a sensitivity chip that's missing</a>," Aniston said of Pitt in an interview with <em>Vanity Fair </em>.

  • Elizabeth Taylor

    After third husband Mike Todd died, Elizabeth Taylor <a href="http://articles.nydailynews.com/2010-09-26/gossip/29440604_1_harry-karl-crooner-eddie-fisher-reynolds-for-elizabeth-taylor" target="_hplink">reportedly found comfort in the arms</a> of Todd's best friend, Eddie Fisher, who was married to actress Debbie Reynolds at the time. Soon after leaving Reynolds, <a href="http://www.time.com/time/magazine/article/0,9171,2022650,00.html" target="_hplink">Fisher and Taylor married</a>, making him the screen siren's fourth husband. When asked about her role in the dissolution of Fisher's marriage, <a href="http://news.google.com/newspapers?nid=1948&dat=19580911&id=j-YwAAAAIBAJ&sjid=HeAFAAAAIBAJ&pg=2835,1438181" target="_hplink">Taylor reportedly said</a>, "You can't break up a happy marriage. Debbie's and Eddie's never has been." As for Reynolds, she's apparently moved on from the affair. "I don't blame Elizabeth now -- now that I have more of a brain about it. At the time it was just such a shock to me," the star <a href="http://www.oprah.com/oprahshow/Carrie-Fisher-and-Debbie-Reynolds/7#ixzz1wwsVYHbi" target="_hplink">told Oprah in February 2011</a>.

  • Gerard Butler

    Before leaving for a <a href="http://www.radaronline.com/exclusives/2012/02/gerard-butler-completed-rehab-home-good-health" target="_hplink">three-week rehab stint</a>, Radar Online alleged that Gerard Butler had <a href="http://www.radaronline.com/exclusives/2012/03/gerard-butler-broke-marriage-home-wrecker" target="_hplink">broken up the marriage</a> of an unnamed newlywed actress. "They would exchange heated text messages, emails and phone calls," an anonymous source told the site. "She thought Gerard wanted to be in a relationship with her but then she found out he was involved with other girls, and hadn't been exactly honest with her about what was going on in his life."

  • Tori Spelling and Dean McDermott

    Tori Spelling and Dean McDermott <a href="http://blog.sfgate.com/dailydish/2008/03/13/spelling-knew-her-marriage-was-in-trouble-after-cheating/#ixzz1OFbjMEQl" target="_hplink">reportedly slept together</a> the first night they met, though they were each married to different people at the time -- Spelling to actor Charlie Shanian and McDermott to Mary Jo Eustace, with whom he had <a href="http://www.people.com/people/article/0,,20040326,00.html" target="_hplink">just adopted a newborn baby</a>. Spelling <a href="http://www.people.com/people/article/0,,1117511,00.html" target="_hplink">divorced Shanian</a> in October 2005, merely 15 months after their $1-million wedding, and <a href="http://www.people.com/people/article/0,,1191681,00.html" target="_hplink">eloped with McDermott</a> the following May. In her book "<a href="http://www.huffingtonpost.com/2011/02/23/celebrity-divorce-memoirs_n_826871.html#s244474&title=sTORI_Telling_by" target="_hplink">sTORI Telling</a>," which was published in 2008, the actress wrote of her split from Shanian: "It needed to end, but it could have happened in a nicer way." Spelling and McDermott, who star in the reality show, "Tori & Dean: Home Sweet Hollywood," recently announced that they're <a href="http://www.huffingtonpost.com/2012/03/23/tori-spelling-pregnant-baby-4_n_1375807.html" target="_hplink">expecting a fourth child</a>.

  • Madonna

    In July 2008, Alex Rodriguez's wife, Cynthia Scurtis, <a href="http://sports.espn.go.com/mlb/news/story?id=3475674" target="_hplink">filed for divorce from the New York Yankees slugger</a>. In her filing, she accusing him of emotional abandonment, "marital misconduct" and extramarital affairs. According to <em>The Telegraph</em>, Scurtis believed the the three-time M.V.P. was having an affair with <a href="http://www.telegraph.co.uk/news/celebritynews/2251995/Madonna-blamed-for-Alex-Rodriguezs-divorce.html" target="_hplink">Madonna</a>, who was married to Guy Ritchie at the time. The popstar denied the claims, insisting that she and A-Rod <a href="http://www.telegraph.co.uk/news/celebritynews/2251995/Madonna-blamed-for-Alex-Rodriguezs-divorce.html" target="_hplink">were just friends</a>.

  • Russell Crowe

    In July 2000, Meg Ryan and Dennis Quaid <a href="http://www.ew.com/ew/article/0,,276771,00.html" target="_hplink">announced they were separating</a> amid allegations of an affair between Ryan and her "Proof of Life" co-star Russell Crowe. A month before the filing, Ryan and Crowe were allegedly seen "cuddling, hugging, kissing" on-set, a <a href="http://www.people.com/people/archive/article/0,,20131801,00.html" target="_hplink">source told <em>People</em> magazine</a>. Quaid and Ryan's divorce was <a href="http://blog.sfgate.com/dailydish/2008/09/29/quaid-denies-ryan-is-moving-for-full-custody-of-son/" target="_hplink">finalized in 2001</a>. Meanwhile, the actress' relationship with Crowe <a href="http://www.usmagazine.com/celebrity-news/pictures/stars-caught-cheating-2009318/2771" target="_hplink">reportedly fizzled out</a> after a few months.

  • LeAnn Rimes And Eddie Cibrian

    In April 2009, rumors surfaced that LeAnn Rimes and Eddie Cibrian -- both married at the time -- were <a href="http://www.huffingtonpost.com/2009/03/17/leann-rimes-and-eddie-cib_n_176129.html" target="_hplink">having an affair</a> on the set of television movie "Northern Lights." Cibrian released a statement <a href="http://www.huffingtonpost.com/2009/03/17/leann-rimes-and-eddie-cib_n_176129.html" target="_hplink">denying the accustations</a>, while Rimes neither denied nor confirmed them. But, by December 2009, Rimes' husband, Dean Sheremet <a href="http://www.huffingtonpost.com/2009/12/19/leann-rimes-husband-files_n_398050.html" target="_hplink">had filed for divorce</a> -- a move that came just three months after Cibrian <a href="http://www.huffingtonpost.com/2009/12/19/leann-rimes-husband-files_n_398050.html" target="_hplink">split from Brandi Glanville, his wife of eight years</a>. Rimes and Cibrian <a href="http://www.huffingtonpost.com/2011/04/23/leann-rimes-eddie-cibrian-married_n_852841.html" target="_hplink">wed in April 2011</a>. Rimes later opened up about the circumstances <a href="http://www.huffingtonpost.com/2011/04/25/leann-rimes-on-affair-wit_n_853535.html" target="_hplink">surrounding her split and remarriage</a>, telling Great American Country, "I didn't have the tools to know how to do it the right way... I'm not glad it happened, but I know why it did."

  • Sienna Miller

    In 2008, Balthazar Getty had a highly publicized affair with Sienna Miller, culminated in a <a href="http://www.popsugar.com/NSFW-Topless-Photos-Sienna-Miller-Balthazar-Getty-Italy-1796219" target="_hplink">series</a> <a href="http://www.popsugar.com/Photos-Topless-Sienna-Miller-Balthazar-Getty-1787723" target="_hplink">of NSFW photos</a> of the pair enjoying an Italian getaway. Getty and his wife, Rosetta, soon separated, but by September 2010 the Gettys were <a href="http://www.huffingtonpost.com/2010/09/20/balthazar-getty-wife-rose_n_731137.html" target="_hplink">back together and opening up to <em>Harpers Bazaar</em></a> about the "challenging time" in their marriage. "I loved and missed my family too much not to make it work," the actor told the magazine.

  • Ben Affleck

    Ben Affleck and Jennifer Lopez met on the <a href="http://www.usatoday.com/life/people/2004-01-23-bennifer-timelilne_x.htm" target="_hplink">set of box-office bomb "Gigli" in early 2002</a>, while Lopez was married to second husband, Cris Judd. Three days before Lopez filed for divorce from Judd in July 2002, <em>People</em> reported that the actress was already introducing Affleck as her "<a href="http://www.people.com/people/archive/article/0,,20137732,00.html" target="_hplink">new boyfriend</a>" to friends. Though the pair known as Bennifer became engaged in November 2002, the relationship was over for good <a href="http://www.usatoday.com/life/people/2004-01-22-bennifer-breakup_x.htm" target="_hplink"> by January 2004</a>.

  • Evan Rachel Wood

    Dita Von Teese filed to divorce rocker Marilyn Manson in December 2006, after one year of marriage. Sources told <em>People</em> magazine that Manson's <a href="http://www.people.com/people/article/0,,20007918,00.html" target="_hplink">relationship with the Evan Rachel Wood played a part</a> in Von Teese's decision to file for divorce, though Wood claimed that she and Manson were merely <a href="http://www.people.com/people/article/0,,20045566,00.html" target="_hplink">"movie buddies" and only got together after</a> he and and his wife had split. Manson and Wood <a href="http://www.people.com/people/article/0,,20335115,00.html" target="_hplink">became engaged</a> in January 2010, but by <a href="http://www.people.com/people/article/0,,20413552,00.html" target="_hplink">August 2010</a> the pair had reportedly gone their separate ways.

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