More from EW
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Evan Rachel Wood and Shane West ('Once and Again')
The former Once and Again co-stars began playing siblings Eli and Jessie when West was in his early 20s and Wood was just 12. Years later, in 2009, the two reconnected and fueled dating rumors when they were spotted holding hands at a club. “I think you can put two and two together,” Wood said at the time. “I won’t confirm nor deny it but I don’t think I have to.”
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Michael C. Hall and Jennifer Carpenter (Dexter)
The duo starred as Dexter and Debra Morgan, respectively, a brother-and-sister pair of crime fighters. (Debra as a homicide detective; Dexter as a blood splatter analyst—and a vigilante serial killer.) The real-life couple dated for nearly three years, marrying in December 2008 and splitting in 2010.
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Ian Somerhalder and Maggie Grace (Lost)
The actors reportedly dated after both were killed off the drama – they played stepsiblings and ex-lovers (!) Boone and Shannon – though Somerhalder kept mum in a 2006 interview with People on the romance between them, saying, “Oh, let’s not go there. No.”
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Maureen McCormick and Barry Williams (The Brady Bunch)
McCormick and Williams played siblings Marcia and Greg on the long-running sitcom, but began a real-life romance on set in Hawaii in 1972. McCormick later revealed to People she had a crush on her co-star from the beginning, and when they finally kissed, she remembered, “A part of me—admittedly a tiny part—said to myself, ‘Oh my God! I’m kissing my brother.’”
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Will Arnett and Amy Poehler (Blades of Glory)
The comedic couple had been married for nearly a decade before separating in 2012. During their marriage, they often appeared on each other’s projects: Poehler played the wife to Arnett’s Gob Bluth on Arrested Development, while Arnett guested on Parks and Recreation. Together, they played a villainous brother-sister figure-skating team in Blades of Glory.
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Lauren Graham and Peter Krause (Parenthood)
They’re the elder Braverman siblings on Parenthood, but off-screen, the two began dating in 2010 after being friends for more than a decade—and years after Graham’s Gilmore Girls co-star Kelly Bishop tried to set them up.
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Michael Emerson and Carrie Preston (Lost)
Preston appeared on husband Michael Emerson’s drama for one episode, “The Man Behind the Curtain,” which traced the history of his character, Ben Linus. In flashbacks revealing Ben’s mysterious past and connections to the Island, she played Ben’s mother, who dies in childbirth.
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Matthew Broderick and Jennifer Grey (Ferris Bueller’s Day Off)
The Ferris Bueller’s Day Off co-stars — she played Ferris’ jealous sister Jeanie — dated briefly in the late '80s. In 1987, just before Dirty Dancing hit theaters, the two were in a car accident that severely injured Broderick, left Grey with chronic pain, and killed the passengers of the other car. Reflecting on that tumultuous year, Grey later told People, “The juxtaposition of that deep sorrow, the survivor’s guilt… and then being celebrated as the new big thing just didn’t jibe… It didn’t feel good to be the toast of the town.”
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Hayden Panettiere and Milo Ventimiglia (Heroes)
On screen, he saved the cheerleader. Off-screen, he dated her, from 2007 to 2008. In the show, Ventimiglia’s Peter Petrelli was revealed to be the uncle to Panettiere’s Claire, a key plot point that tied together several of the original characters on the superhero drama.
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Chris Pratt and Emily VanCamp (Everwood)
Long before she lusted for revenge on, well, Revenge, and long before he hunted dinosaurs in Jurassic World (or aliens in Guardians of the Galaxy, or “network connectivity problems” on Parks and Recreation), VanCamp and Pratt played siblings on the WB drama from 2002 to 2006. They quietly dated while starring on the show and broke up in 2007.
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Dave Annable and Emily VanCamp (Brothers and Sisters)
Their characters Justin and Rebecca began the family drama as half-siblings, but when Rebecca later revealed she wasn’t related to him at all, the two eloped as a couple in the fourth season. The actors themselves dated as well, from 2007 to 2008.
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David and Tamela Mann (Meet the Browns)
The married couple — both actors, though Tamela is also a gospel singer — had been together for more than 25 years before playing father and daughter on Tyler Perry’s Meet the Browns, the TBS sitcom spun off from Perry’s Madea films. The pair currently stars on BET’s reality series It’s a Mann’s World.
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Joely Richardson and John Hensley (Nip/Tuck)
Richardson played Julia, the frustrated stay-at-home mother to John Hensley’s troubled teenager character Matt, on the FX drama. During the early 2000s, the two were rumored to be dating, though neither ever commented on the rumors.
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John Travolta and Diana Hyland (TV movie Boy in the Plastic Bubble)
The two had entered into a relationship after starring as mother and son in the ABC TV movie The Boy in the Plastic Bubble, until Hyland died of cancer at 41. “I gave her great joy the last months of her life,” he told People in 1977. “I always feel she is with me — I mean her intentions are. Diana always wanted the world for me in every possible way.”
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David Tennant and Georgia Moffett (Doctor Who)
The two played relatives on the timey-wimey drama in 2008 when Moffett appeared on the series to play the artificially created daughter of Tennant’s Tenth Doctor. They married in December 2011, and have three children.
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Katherine Heigl and Jason Behr (Roswell)
When Heigl made her TV debut at age 20 on the WB’s Roswell as Isabel, an orphaned alien disguised as a high school student, she met Behr, who played Isabel’s also-extraterrestrial brother Max. They dated off-screen, ending the relationship around the time the series went off air in 2002.
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Shannen Doherty and Jason Priestley (Beverly Hills, 90210)
They played twins on the TV phenomenon of the early 1990s, and off-screen, they became teen icons. Though they fielded rumors they dated for decades, Priestley later revealed on The Howard Stern Show he and Doherty dated briefly from 1990 to 1991 — though, he added, “various combinations of people slept with each other over the years. If you were in that situation, trust me, you would have done it too.”
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Selena Gomez and David Henrie (Wizards of Waverly Place)
Gomez has repeatedly denied she dated her Wizards of Waverly Place costar — the duo played wand-wielding siblings on the Disney Channel comedy — but she and Henrie sparked romance rumors in 2010 and 2014 after being photographed together.