Amy Poehler and Will Arnett

When working with someone day in and day out for a movie, there’s a possibility some sparks may start to fly. Or, in the case of Amy Poehler and Will Arnett, you may already be married when asked to star as brother and sister in a movie.
In the film Blades of Glory, Poehler and Arnett played a brother and sister figure skating duo. Let’s hope some googly side eyes weren’t caught on camera between the two lovebirds. But, if you’ve seen the movie, you may remember an on-screen kiss between the skating duo, which was totally gross. Well, in an interview, Poehler revealed that that kiss was actually shared between doubles. Who knew there was such a thing as kiss doubles? Maybe the brother-sister roles on screen were the real reason they ended up divorcing?
Susan Dey and David Cassidy

While it all may be just hearsay that these two on-screen siblings dated in real life, Susan Dey and David Cassidy were part of The Partridge Family as singing and performing brother and sister.
Maybe the feelings were just one-sided, or maybe Cassidy didn’t want to reveal his true feelings about his on-screen sister, but in his autobiography, “C’Mon Get Happy,” he explained that romantic feelings were not there for this Partridge family sister. In fact, he even went on to say, “Susan lacked the slutty aspect of a female that I always found so attractive.” Okay, there big guy. I guess dating your sis wasn’t slutty enough for him.
Robert Pattinson and Nikki Reed

While it’s no secret Robert Pattinson and Kristen Stewart dated on and off while filming the Twilight saga films, Pattinson reportedly dated his onscreen sister too! Say what?
According to some sources, the eye-catching vampire also dated Nikki Reed, who played Rosalie Hale in the movies. While their fling was most definitely short-lived and technically all the Cullen children were adopted, the romance was still there despite their on-screen family life. I guess these vampires had more than one secret up their sleeves.
Jamie-Lynn Sigler and Robert Iler

Secrets, secrets are no fun. But it seems these two TV siblings had an off-screen secret of their own. Jamie-Lynn Sigler and Robert Iler starred in the hit HBO show The Sopranos. They played siblings Meadow and A.J. on the show.
And while the two may have denied questions about their real-life romance, they were definitely seen getting close a time or two. At least, closer than any friends or siblings may get. While only these two may know if there was an actual romance or not, one thing’s for certain, getting cozy with your sis is definitely just as creepy.
Dave Annable and Emily Van Camp

Dave Annable and Emily Van Camp may have started out as siblings on ABC’s show Brothers & Sisters, but it didn’t take long for producers to quickly change their mind about the two. The two had so much chemistry off the show, the producers wanted to capitalize on that romance on-screen too.
In the show, Annable and Van Camp played brother and sister Justin and Rebecca. However, the producers changed the storyline of the show so that the two were no longer related allowing them to be able to hook up on AND off screen. Well, that sure is a commitment now isn’t it?
Milo Ventimigilia and Hayden Panettiere

Milo Ventimiglia may have had his hand at bad boy romance with Rory on Gilmore Girls, but his romance with Hayden Panettiere is definitely the most controversial considering their roles in the NBC show Heroes.
While they may not have played brother and sister on screen, their relationship to one another on and off screen is still one to be talked about. For four seasons they played Peter and Claire on the show. In the show, Claire was adopted and we later find out she is the daughter of Peter’s brother. So in reality, they’re uncle and niece. That’s an awkward family reunion.
Michael C. Hall and Jennifer Carpenter

Some people have many good and bad qualities about them, but a murderer, murder solver, AND someone who dates their sibling?! Wow, Dexter!
Okay, okay, maybe the dating happened in real life to a girl who was only his on-screen sister. Michael C. Hall and Jennifer Carpenter play brother and sister in the Showtime series Dexter. While Dexter may have been adopted, he and Debra Morgan are siblings none the less. While playing on-screen brother and sister, the two were actually married in real life. Maybe all the brother and sister fighting on screen led to their real-life divorce in 2010. Or maybe, it was normal couple issues. Your guess is as good as mine.
Emily Van Camp and Chris Pratt

It seems Emily Van Camp had a habit of dating her on-screen siblings. No, no not her siblings in real life, just her TV and movie fam.
Van Camp and Chris Pratt starred in the WB Show Everwood as brother and sister Bright and Amy Abbott. The two sibling lovebirds couldn’t keep their hands off each other and actually dated for about two years in real life. But, their family romance didn’t last forever and they ended up breaking up in 2007. Looks like they may have some awkward family dinners in their future.
Ian Somerhalder and Maggie Grace

Unlike many others on this list, sparks seemed to fly on AND off screen for these two lovebirds and siblings. Yes, you read that right. Ian Somerhalder and Maggie Grace played step brother and sister Boone and Shannon on ABC’s hit show Lost.
While the two dated briefly in real life, it seemed the sparks continued to their on-screen roles and the two even shared a kiss during the show. Even though they were just stepbrother and sister, that is still gross! But sometimes, you just can’t stop true love, can you?
Jason Priestly and Shannen Doherty

There’s nothing like dating your twin, right? I mean, after all, they do share quite a bit in common with you so what could there be to argue about?
But in all seriousness, during the first season of Beverly Hills, 90210, twins Brandon and Brendan Walsh (played by Jason Priestley and Shannen Doherty) moved from the midwestern lifestyle to right in the middle of LA. Priestley admitted during a Howard Stern interview that he and Shannen Doherty had actually dated during the first season of the show. Talk about double trouble and an awkward sibling rivalry once the two broke up!
Maureen McCormick and Barry Williams

So maybe they weren’t biological siblings in the show, but Marcia Brady and Greg Brady from The Brady Bunch struck up a little love interest of their own off-screen. Played by Maureen McCormick and Barry Williams, the two just couldn’t fight back the feelings.
McCormick talked about the relationship in her memoir, Here’s the Story: Surviving Marcia Brady and Finding My True Voice, “We couldn’t hold back any longer. It was our first kiss, and it was long, passionate and deep… though as we continued to kiss and press against each other so closely… a part of me – a tiny part, admittedly – said to myself, `Oh my God! I’m kissing my brother. What am I doing?'”
Selena Gomez and David Henrie

Anyone out there remember Disney Channel’s Wizards of Waverly Place? It was all about a family of wizards, obviously, but there were some shenanigans going on behind the scenes.
Brother and sister wizards, Alex and Justin, created some magic of their own off-screen too. It is reported that Selena Gomez and David Henrie, who played the two siblings, had a little love spell of their own after Gomez and Justin Bieber split in 2014.
Lauren Graham and Peter Krause

Oh how we love Lauren Graham. From her role in the hit series Gilmore Girls to her time on Parenthood, she’s always been a fan favorite. Apparently, her brother on the show Parenthood, Peter Krause, was a fan as well.
On Parenthood, Krause played leading role Adam Braverman and Graham played his sister, Sarah. The two have actually been together since 2010. One might find it a little odd kissing your on-screen sister every night before bed, but hey, if they can dig it, so can we.