Cupid's arrow can hit at any time, but what if when you find your one true love you are already taken? Find out which celebrities risked it all...

Tori Spelling, 49, and Dean McDermott, 56, have been married since 2006, but they actually met in 2005 while filming ‘Mind Over’ together. At the time, they were married to Charlie Shanian and Mary Jane Eustace, respectively. However, in her ‘True Tori’ TV show, the ‘Saved by the Bell’ actress revealed that she and Dean had sex the very first night they met. She said: “It wasn't like, ‘Oh, just get your rocks off, have sex with someone just to have sex,’ you know? It was a conscious decision, like, fell head over heels for you.”

It was a love triangle that made headlines across the globe and involved King Charles III, 74, Camilla, Queen Consort, 75, and the late Princess Diana. In 1996, when Queen Elizabeth II’s eldest son was married to Lady Di, he began an affair with Camilla - whom he had met in the '70s and whom he had already dated briefly. Charles and Diana announced their separation in 1992, with Charles publicly admitting to his affair with Camilla two years later. In an interview with ITV, after being asked if he had been “faithful and honorable” to Princess Diana, Charles answered: "Yes… until it became irretrievably broken down, us both having tried." Charles and Camilla married in 2005 and are still together.

Antonio Banderas, 62, and Melanie Griffith, 65, were married from 1986 to 2015. The Hollywood stars met on the set of ‘Two Much’, when they were married to Ana Lenz and Don Johnson, respectively. Reflecting on their marriage, Banderas once said in an interview with ABC News: "It was very, very fast and very compulsive, but at the same time, we were tied at the time. We tried as much as we could to be respectful. We just thought this may be one of those, you know, infatuation moments that we have when we shoot movies because we got to play together a couple, so let's just go home.” The next thing that happened was that they divorced from their respective partners.

Angelina Jolie, 47, met Billy Bob Thornton, 67, on the set of ‘Pushing Tin’, back in 1999, getting married just a couple of months later. However, at the time he was in a serious relationship with actress Laura Dern (‘Marriage Story’, ‘Jurassic Park’), which precisely ended due to his romance with Jolie. In an interview with Talk magazine, Dern recalled how things went for her. She said: “I left our home to work on a movie, and while I was away, my boyfriend got married, and I’ve never heard from him again.” As for Thornton, he once told The Guardian: "Others may say that you left our girl and married someone else. But it made me happy and somebody else happy. I'm sorry it caused pain."

Angelina Jolie’s relationship with Billy Bob Thornton is not the only love triangle she has been involved in. In fact, when she met her now ex Brad Pitt, 59, on the set of ‘Mr. and Mrs. Smith’, he was married to 'Friends' star Jennifer Aniston, 54. For a long time, it was believed Jen and Brad separated due to his relationship with Angelina, and in 2008 he confessed to Rolling Stone magazine that he “fell in love” while filming the 2005 movie. Later on, Angelina spoke about her family with The New York Times and said: “Not a lot of people get to see a movie where their parents fell in love.”

Country music star LeAnn Rimes, 40, and ‘CSI: Miami’ actor Eddie Cibiran, 49, tied the knot in 2011 and they’e still together. However, when they met in 2008 on the set of ‘Northern Lights’, they were married to Dean Sheremet and Brandi Glenville, respectively. Rumors about an affair quickly surfaced. While the pair denied everything, a friend of Rimes told PEOPLE that “there are some feelings,” although she did not know “if she’s done with her marriage". In 2009, both LeAnn and Eddie ended their respective relationships. Later on, Rimes said: “I take responsibility for everything I’ve done. I hate that people got hurt. But I don’t regret the outcome.”

Country music star Jason Aldean, 45, and former ‘American Idol’ contestant Brittany Kerr, 34, were spotted sharing a kiss back in 2012, year when he was married to Jessica Ussery. While Aldean publicly apologized for his behavior and tried to save his marriage, this ended in 2013. Two years later he tied the knot with Kerr. They’re still together.

'Homeland' star Claire Danes, 43, had a four-year relationship with ‘Almost Famous’ actor Billy Crudup, 54. When their romance went public, their fans were left speechless as Crudup had left his then-wife Mary Louise-Parker, who was pregnant. In a 2015 interview with Us Weekly, Danes reflected on her relationship with Billy by saying: "I was just in love with him. And needed to explore that and I was 24… I didn’t quite know what those consequences would be.”

Actor Kelsey Grammer (‘Frasier’, ‘Cheers’), 68, met his current wife Kayte Walsh while he was still married to Camille Grammar. While Walsh once told Oprah Winfrey that she was “not proud” of how things happened, Camille took a step forward and opened up about her failed relationship with Grammer. Speaking to ‘Good Morning America’ Katie Couric she said: "My, my whole life was falling apart. My husband left me. He was having an affair with another woman in New York City."

In 2005, country music stars Blake Shelton, 46, and Miranda Lambert, 39, took the stage of CMT 100 Greatest Duets Concert, where they performed together ‘You’re The Reason God Made Oklahoma’. The spark between these two was quite evident, but Shelton was married to Kaynette Williams at the time. In an interview with Dateline in 2011, Lambert said: "I knew he was married. I had seen their wedding pictures in Country Weekly. I knew better, like, 'This is off-limits.'” Shelton, on the other hand, said in an appearance on VH1’s ‘Behind The Music”: "I've never had that kind of experience with anybody. I was a married guy, you know? Looking back on that, I was falling in love with her, right there on stage." Although the pair has said their romance officially began in 2006, Miranda told CMT Insider in 2008 that “it’s been three long years already.” They were married from 2011 to 2015.