15 On-Screen Couples You Definitely Didn't Realize Were Actually a Thing

We all know that celebrities love to hook up with their onscreen love interests and sometimes those hookups turn into serious relationships and eventually marriage like Brad Pitt and Angelina Jolie, Amber Heard and Johnny Depp, and Ben Affleck and Jennifer Garner (all three of which, sadly, ended in divorce). But not every one of these hookups ends in a relationship. Sometimes some messy hookups that happen off-screen turn into short flings that happened so fast, barely anyone even noticed (or remembers).

Sometimes the stars of movies and TV shows are encouraged to begin a relationship with their costar in order to get more press for the project (such as Shailene Woodley and Theo James *probably* and Kristen Stewart and Robert Pattinson *probably*). But sometimes costars are forbidden from hooking up behind the scenes so the stars sometimes just keep the relationship on the DL so they don't get in trouble (it doesn't usually work). Then there are those scandalous stories where onscreen love interests got it on off-screen even though they were already in a committed relationship and those are the kinds of stories that get everyone talking. These are the stories of co-stars who hooked up when the cameras weren't rolling but the fling fizzled out before anyone even really noticed.

15 A Magical Romance

You might think that none of the Harry Potter actors hooked up behind the scenes but you would be wrong. There is one onscreen couple that may not have completely been an act. We all know that Robert Pattinson hooked up with his Twilight co-star, Kristen Stewart, but he was rumored to have hooked up with co-star Katie Leung. Before he was a vampire, Pattinson was a the handsome young wizard, Cedric Diggory and Leung was his onscreen love interest, Cho Chang. Though Harry Potter may have had a crush on Cho first, it was Cedric who won her heart and it was Pattinson who seemed to have won Leung's as well. Though the two never confirmed their relationship, they were spotted getting very close a few times off set but it fizzled out soon after the movie premiered. Pattinson moved onto his next big role in a giant franchise but, this time, as the lead with Twilight and the rest is history.

14 Age is Just a Number

Back before Ryan Reynolds became the huge star he is today (and before his alleged nose job), he was in a movie alongside Sandra Bullock called Murder by Numbers back in 2002. The two don't exactly play love interests in the movie (but they do get awful close) but they fell in love offscreen and the relationship lasted about a year before they called it quits. Despite the 16-year age difference, the two seemed to really care about each other and Gosling said that both Bullock and Rachel McAdams were two of the "greatest girlfriends of all time"--that was before he met his current partner Eva Mendez, of course. Gosling met two of his greatest loves on the set of one of his movies and, true to his brand, he met Eva Mendes on the set of The Place Beyond the Pines and the couple now has two daughters together.

13 She Broke His Heart… Maybe

We all know that Vanessa Hudgens and Zac Efron dated after starring in three High School Musical movies but you might not know that Hudgens dated another costar after her five-year relationship with Efron had ended. After Hudgens and Josh Hutcherson met on the set of Journey 2: The Mysterious Island, they had a quick fling that they never confirmed after after they had already broken up. They really seemed like a great couple together because they are both short and adorable but the fling only lasted for a few months. After their relationship ended, they were asked if they were dating in an interview and Huterson joked and said, "We were at one point, but she broke my heart. I'm just kidding. That was a while ago, we're just really good friends now.” Now Hutcherson is dating his Escobar: Paradise Lost co-star Claudia Traisac and Hudgens is dating the Switched at Birth star, Austin Butler.

12 Before Marvel, There was Gossip Girl

We all know that Blake Lively and Penn Badgley were an item for years after meeting on the set of Gossip Girl and then Lively met her husband, Ryan Reynolds, on the set of The Green Lantern. However, there is one other little known onscreen Gossip Girl romance that happened offscreen as well. Before Sebastian Stan became Captain America's best bud in the Marvel movies, he appeared on Gossip Girl as Carter Baizen who actually didn't like Leighton Meester's character, Blair Waldorf, too much but they definitely hit it off while the cameras weren't rolling. Sadly, the relationship soon fizzled out and the two went their separate ways. The relationship didn't seem to end on good terms because Meester called her ex "stupid" in her album that was released 5 years after their breakup. Too bad we can't just go back in time and live in 2009 forever.

11 A Very, Very Special Relationship

Let's take a trip back to the 90s when Buffy the Vampire Slayer was one of the hottest shows on TV and Sarah Michelle Gellar and David Boreanaz had one of the hottest relationships on TV as the high school vampire killer, Buffy, and the brooding vampire, Angel. Did the two ever hook up in real life? Back before Boreanaz met and married his current wife Jaime Bergman in 2001 and Gellar married her I Know What You Did Last Summer costar, Freddie Prinze Jr. in 2002, there were rumors flying around about the two dating after they were photographed kissing and hugging at some Hollywood events so though they never confirmed their relationship, it seems that they were, at the very least, hooking up. According to Gellar, the two had a "very, very special relationship" so you can interpret that however you'd like.

10 Mr. and Mrs. Aniston

After Brad Pitt left her for his Mr. and Mrs. Smith costar, Angelina Jolie and before she hooked and married with her Wanderlust costar, Justin Theroux, Jennifer Aniston had a fling with her onscreen love interest in The Break-Up, Vince Vaughn. Though both of them went to great lengths to deny the relationship, it was pretty obvious they were together after they were spotted kissing and cuddling at various spots in Hollywood and Aniston even met his mom! Almost ten years later in 2015, Vaughn was asked about his alleged relationship with Aniston and he finally acknowledged that the two were together but he couldn't handle all of the attention that she was getting--especially considering that it was just a year after she divorced Brad Pitt. However, the two are still good friends and he was even invited to her wedding to Justin Theroux.

9 He Likes Brunettes

Matt Damon has had some very famous girlfriends over the years such as Minnie Driver and Wynona Ryder but he is now happily married to his non-celebrity wife, Luciana Barroso (can you tell he has a thing for brunettes?). Penelope Cruz has also had relationships with a few of her onscreen love interests such as Tom Cruise, Matthew McConaughey, and her now-husband, Javier Bardem. However, you might not know that Damon and Cruz had a quick fling after they starred in the western flick, All the Pretty Horses way back in 2000. The two even appeared on Oprah together to promote the movie but they did not confirm their relationship--but the two seem to be very smitten with each other and were often pictured holding hands. The two did not stay together for very long but there doesn't seem to be any hard feelings between them--after all it was 17 years ago!

8 Before Ben and Jen, There was Ben and Gwen

Ben Affleck and Gwyneth Paltrow have both had some very high profile relationships over the years but most people forget that the two actually dated each other for a time. Affleck dated two of his onscreen love-interests, Jennifer Lopez and Jennifer Garner while Paltrow had relationships with three of hers: Brad Pitt, Viggo Mortensen, and Luke Wilson. The two were in a brief, on-again-off-again relationship between 1999 and 2000 while filming Bounce and Shakespeare in Love. Paltrow later said that she loved Affleck but he just wasn't ready and he was more interested in having a good time. While they were still together, Paltrow even said in an interview that the perfect woman for Affleck was "anything that serves cold beer in a bikini.” Yep, that definitely sounds like him. Regardless of bikinis and beer, the two both say that they remain good friends.

7 Me, Myself, & Renee

Rene Zellweger has many odd, rumored (and some not-so-rumored) flings such as Matthew Perry, George Clooney, John Krasinski, John Stamos, and Bradley Cooper but her hookup with Jim Carrey is one of the weirdest. The two met on the set of Me, Myself, & Irene back in 2000 and they had a fling and were even rumored to be engaged at one point. There is also a rumor that Carrey broke up with Zellweger after she pressured him to get married as soon as possible. Considering that he had already been married and divorced twice, he probably didn't think that marriage was right for him at the time. Luckily for the Chicago star, she dodged a bullet with Carrey considering he has a pretty bad track record with relationships. Before Zellweger, Carrey was rumored to have hooked up with his Ace Ventura co-star, Courteney Cox, but never hooked up with another one of his costars again (at least, not that we know of).

6 A Disney Romance

Kate Mara may now be married to her Fantastic Four costar, Jaime Bell, but before she was married, she hooked up with her Stone of Destiny costar, Charlie Cox and even her We Are Marshall director, McG. However, she was also rumored to have had a fling wth former Disney star, Shia LaBeouf after they starred in the movie, Man Down in 2015. LaBeouf also has a history of dating his costars such as Megan Fox and Carey Mulligan but Mara is his most recent onscreen/offscreen fling. Though the two never confirmed their relationship, they were spotted at Disneyland together looking very cozy together but also pretty low-key. While the two of them were doing press for the movie, she often gushed about her rumored boyfriend in interviews, saying that he was "one of the best actors of our generation" which is very generous.

5 It Wasn't Meant to Be

Kirsten Dunst and Garrett Hedlund were always a very private couple which is probably why it seemed like they were only together for a moment even though they dated for four years. The two started dating in 2010 after they met on the set of On the Road and, according to Hedlund, their first date together was a midnight canoe ride (how cute is that?!) and they even walked the red carpet together for the Golden Globes in 2016, just before they called it quits. According to the tabloids, the relationship was rocky leading up to the split and that they "weren't on the same page when it came to their future." Dunst did not seem too upset about the breakup because she was soon spotted cuddling up with her Fargo costar, Jesse Plemons, and the two were engaged not long after that. She sure moves fast!

4 Forget Jim and Pam

Nope, it wasn't Jim and Pam who had an offscreen relationship, it was actually Jim and Karen who had a secret fling. When Rashida Jones appeared on The Office as Karen, the new love interest of Jim (John Krasinski), the two seemed to get along really well and were spotted getting pretty close while the cameras weren't rolling. The two never confirmed their relationship so it seemed that it was a quick fling and the two of them just weren't meant to be--just like Jim and Karen. After hooking up with Tobey McGuire, Charlie Hunnam, Garrett Hedlund, Colin Jost, and Obama's former speechwriter Jon Favreau, she is now dating Vampire Weekend Frontman, Ezra Koenig. Krasinski is now married to Emily Blunt and they will be playing husband and wife in the upcoming thriller, A Quiet Place, which is also directed by Krasinski.

3 Carrie Bradshaw and Iron Man

Way back before Carrie Bradshaw and Iron Man, there was Sarah Jessica Parker and Robert Downey Jr. who started dating in 1984 after they starred in Firstborn together. Though the two of them have remain friends over the years, Parker has since said that Downey taught her "little bit about being a parent" because dating him was like taking care of a child. For years, Downey was known as a bit of a bad boy who liked to drink a lot and also had some pretty nasty drug habits. Parker decided that she couldn't deal with his addiction any longer so they split up 1991. Seven years is a long time to be with someone you have to treat like a child! Downey has since said that he tried to help her but she was "miffed" when he couldn't get it together. Now, Downey has been married to his wife, Susan Downey, for twelve years and Parker has been married to Matthew Broderick for twenty years.

2 A Very Creepy Romance

For some reason, Marilyn Manson has managed to hook up with some of the hottest ladies in Hollywood and we'll never understand why. After he got a divorce from burlesque Beaty, Dita von Teese, he went public with his relationship to Evan Rachel Wood who he had been having an affair with after they met at a party and he cast her in his music video for "Heart-Shaped Glasses". The two were also costars in Phantasmagoria: The Visions of Lewis Carroll. The relationship was controversial from the start considering that he was 36 and she was 18 but Manson didn't seem to care considering that built his career on controversy. Wood said that she was attracted to Manson because he was "somebody that promised freedom and expression and no judgments" and she was "craving danger and excitement." The two didn't stay together for very long and now Wood is starring in one of HBOs hottest shows, Westworld, and Manson is, you know, doing whatever it is he does.

1 Love in Westeros

Of course, everyone knows that Kit Harrington is engaged to his onscreen love interest Rose Leslie but she's not the only Game of Thrones star that Jon Snow was rumored to have hooked up with. Way back in the first season, long before Daenerys and Jon Snow get a little too close for comfort on the show, it seemed that there was something going on behind the scenes between Harrington and Emilia Clarke. The two have never confirmed that they were ever together but thanks to a 2012 photoshoot for Rolling Stone, we have a lovely photo of the two of them kissing each other, looking very comfortable. The photographer said that she "asked them to kiss, I suppose love was in the air, and I was just lucky enough to be there." They definitely didn't have to be asked twice! Despite their past, Leslie is very close with Clarke and there doesn't seem to be any hard feelings between them.