Ethan Hawke's 2004 divorce from Uma Thurman was marked by allegations of infidelity, and while Hawke has remained adamant that he never cheated, the actor is now opening up about his views on monogamy.

In a recent interview with Mr. Porter, Hawke revealed that he doesn't believe cheating is bad.

"People have such a childish view of monogamy and fidelity," the actor said. "'He's cheated so he's bad, she's cheated so she's bad', as opposed to a recognition that our species is not monogamous."

So what does that mean for his marriage to Ryan Shawhughes, with whom he has two kids?

"My relationship with my present wife is thrilling to me and I'm committed to it. But neither she nor I know what shape the future will come in," he said. "Sexual fidelity can't be the whole thing you hang your relationship on. If you really love somebody you want them to grow, but you don't get to define how that happens. They do."

Hawke and Thurman's six year marriage ended amid rumors of an affair with Shawhughes, his kids' former nanny. He and Shawhughes married in 2008.

Like Hawke, many scientists are baffled as to why humans evolved into monogamous creatures; Dr. Dieter Lukas of the University of Cambridge told the New York Times earlier this year that "monogamy is a problem."

And journalist Meghan Laslocky, the author of "The Little Book of Heartbreak: Love Gone Wrong Through the Ages," recently wrote in a CNN editorial, "It's time for our culture to wake up and smell the sex pheromones: monogamy is not natural for many, or probably even most, humans."

What do you think? Do love and monogamy go hand in hand?

Probably not in Hollywood. Here are more celebs who went on to marry their mistresses.

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  • Eddie Cibrian and LeAnn Rimes

    Eddie Cibrian and LeAnn Rimes' affair reportedly began in 2009 after they met on the set of the <a href="http://abcnews.go.com/Entertainment/InTheSpotlight/leann-rimes-affair-actor-eddie-cibrian/story?id=12032482">Lifetime movie "Northern Lights." </a>At the time, Cibrian was married to<a href="http://abcnews.go.com/Entertainment/InTheSpotlight/leann-rimes-affair-actor-eddie-cibrian/story?id=12032482"> reality star Brandi Glanville</a> and Rimes was married to <a href="http://abcnews.go.com/Entertainment/InTheSpotlight/leann-rimes-affair-actor-eddie-cibrian/story?id=12032482">dancer-turned-food blogger, Dean Sheremet.</a> After <a href="http://www.aceshowbiz.com/news/view/00035772.html">divorcing their respective spouses</a>, the actor and the country singer <a href="http://www.people.com/people/article/0,,20485029,00.html">tied the knot</a> in April 2011.

  • Ethan Hawke

    Ethan Hawke and <a href="http://www.cbsnews.com/8301-505270_162-57444573/ethan-hawke-life-is-good/">wife of six years,</a> Uma Thurman, <a href="http://www.people.com/people/article/0,,1212898,00.html">divorced in 2004</a> amid rumors of his <a href="http://www.guardian.co.uk/film/2012/feb/08/ethan-hawke-interview">affair with the couple's nanny, </a>Ryan Shawhughes. The "Gattaca" actor, however, claims that his relationship with Shawhughes did not begin until <a href="http://www.dailymail.co.uk/tvshowbiz/article-1034692/Yes-married-Ethan-Hawke-admits-tied-knot-childrens-nanny.html">after he and Thurman had split.</a> In June 2008, Hawke and an <a href="http://www.eonline.com/news/57349/ethan-hawke-impregnates-former-nanny">already pregnant</a> Shawhughes <a href="http://www.eonline.com/news/2856/ethan-hawke-a-twice-married-man">got married. </a>

  • Eddie Fisher

    While crooner Eddie Fisher was married to <a href="http://www.foxnews.com/entertainment/2010/09/24/scandalous-love-triangle-time/">America's sweetheart, Debbie Reynolds,</a> he <a href="http://www.dailymail.co.uk/tvshowbiz/article-1268158/Debbie-Reynolds-losing-husband-Eddie-Fisher-Elizabeth-Taylor.html">began an affair</a> with Elizabeth Taylor. The pair got together after <a href="http://www.cbsnews.com/8301-31749_162-20046190-10391698.html">bonding over the mutual loss of Mike Todd</a> -- Fisher's dear friend and Taylor's late husband. <a href="http://www.cbsnews.com/8301-31749_162-20017578-10391698.html">Fisher divorced Reynolds </a>and eventually <a href="http://www.cbsnews.com/8301-31749_162-20046190-10391698.html">tied the knot</a> with Taylor in 1959. The pair <a href="http://www.cbsnews.com/8301-31749_162-20046190-10391698.html">split up five years later </a>when the actress left him for Richard Burton.

  • Elizabeth Taylor and Richard Burton

    Elizabeth Taylor and Richard Burton <a href="http://www.cbsnews.com/8301-31749_162-20046841-10391698.html">began their affair on the set of "Cleopatra"</a> while both actors were <a href="http://www.nypost.com/p/news/opinion/books/furious_love_the_love_letters_taylor_3RREnDd0ABuOMWMFVNDcGO">married to other people</a>. They <a href="http://www.cbsnews.com/8301-31749_162-20046841-10391698.html">divorced their respective spouses</a> -- Eddie Fisher and Sybil Burton -- so they could be together. The couple <a href="http://www.cbsnews.com/8301-31749_162-20046841-10391698.html">tied the knot</a> in 1964, but <a href="http://abcnews.go.com/Entertainment/marriages-liz-taylor/story?id=13202596">divorced ten years later</a> in 1974. They <a href="http://www.usmagazine.com/celebrity-body/pictures/elizabeth-taylors-many-marriages-2011233/13636">gave marriage another go</a> in 1975, but <a href="http://www.usmagazine.com/celebrity-body/pictures/elizabeth-taylors-many-marriages-2011233/13636">split again</a> less than a year later in 1976.

  • Frank Sinatra

    Frank Sinatra <a href="http://www.people.com/people/archive/article/0,,20102763,00.html">began getting close</a> with Ava Gardner in 1948, after <a href="http://www.people.com/people/archive/article/0,,20102763,00.html">meeting the screen siren</a> on the MGM studio lot. The crooner, however, was <a href="http://www.people.com/people/archive/article/0,,20102763,00.html">married and had three children</a> with his wife, Nancy, at the time. The Rat Pack member eventually <a href="http://www.nydailynews.com/entertainment/music-arts/frank-sinatra-love-marriages-article-1.329594">divorced his wife in 1951</a> and went on to marry Gardner <a href="http://www.people.com/people/archive/article/0,,20102763,00.html">just three days later. </a> But their <a href="http://www.people.com/people/archive/article/0,,20102763,00.html">passionate union</a> didn't last. Gardner <a href="http://www.ew.com/ew/article/0,,20261652,00.html">filed for divorce</a> in 1954.

  • Woody Allen

    Woody Allen was <a href="http://www.hollywoodreporter.com/news/pbs-woody-allen-documentary-spotlights-263275">twice divorced</a> when he began his <a href="http://www.express.co.uk/posts/view/99100/Allen-urges-court-to-ban-Farrow">12-year relationship with Mia Farrow</a> in 1980. After more than a decade together, Farrow discovered that Allen was being unfaithful when she <a href="http://www.cnn.com/SHOWBIZ/9712/24/woody.weds/">found naked pictures of Soon-Yi Previn</a> -- her adopted daughter <a href="http://community.seattletimes.nwsource.com/archive/?date=19920818&slug=1508089">from a previous marriage</a> -- in Allen's apartment. In 1997, Allen <a href="http://www.cnn.com/SHOWBIZ/9712/24/woody.weds/">tied the knot</a> with Previn -- who is <a href="http://www.cnn.com/SHOWBIZ/9712/24/woody.weds/">35 years his junior.</a>

  • Tori Spelling and Dean McDermott

    Tori Spelling and Dean McDermott were both <a href="http://www.people.com/people/article/0,,1117511,00.html">married to other people</a> -- she to Charlie Shanian and he to Mary Jo Eustace -- when they met on the set of the <a href="http://www.today.com/id/19254737/site/todayshow/ns/today-entertainment/t/mary-jo-was-tori-deans-other-woman/#.UPneh6HIN4U">Lifetime movie "Mind Over Murder"</a> in 2005. According to People magazine, Spelling realized her <a href="http://www.people.com/people/article/0,,1117511,00.html">marriage was not working</a> and was <a href="http://www.people.com/people/article/0,,1117511,00.html">developing feelings for McDermott</a> during the three-week shoot. After <a href="http://www.people.com/people/article/0,,1117511,00.html">splitting with their respective spouses</a>, they <a href="http://www.people.com/people/archive/article/0,,20175757,00.html">tied the knot</a> in an intimate ceremony in Fiji in May 2006. The pair now have <a href="http://www.usmagazine.com/celebrity-moms/news/tori-spelling-on-raising-four-children-its-overwhelming-2012512">four children together</a>.