These Co-Stars Secretly Dated While Working Together

"It was such a huge part of my life and no one knew about it."

Some things in Hollywood are better off kept a secret -- and sometimes that includes on-set romances. In order to avoid the prying eyes of the paparazzi and avoid potential workplace complications, some actors chose to keep their relationships with co-stars on the down-low.

Although it can get tricky to hide their dating life from other castmates, crew, and fans who've noticed their obvious on-screen chemistry, celebs like Miley Cyrus and Kaley Cuoco chose to keep their romances with co-stars under wraps. Without the input of the public, some of these relationships blossomed while others ended in heartbreak, only to be revealed long after the couple had broken up.

Discover which co-stars were secretly dating below…

1. Alexis Bledel & Jared Padalecki

Alexis Bledel and Jared Padalecki dated both on and off-screen while they were working on "Gilmore Girls" together. The duo never opened up about their relationship and it was actually casting director Mara Casey who revealed they were a couple, many years after the show wrapped.

"We did have a joke about casting all of Alexis' [real-life] boyfriends. She dated Jared and Milo [Ventimiglia]. And she also dated a young New York actor named Chris Heuisler, who played a guest role. Real sweet kid," Mara told Life & Style.

2. Kelly Clarkson & Justin Guarini

Despite years of dating rumors, Kelly Clarkson and Justin Guarini admitted they were actually a couple at one point -- just not when everyone thought! The duo didn't date during their time on "American Idol" together and instead coupled up while somewhere around the time they were filming "From Justin To Kelly."

"We didn't date during 'Idol,' which everybody thought we were dating. We did date...We did date a little bit. I think any two people who are thrown together that much [would eventually date]. 'Timeless,' you put that song on 'From Justin to Kelly' -- you can't fight it!" Kelly said on "Watch What Happens Live!"

3. Brian Austin Green & Tori Spelling

Brian Austin Green and Tori Spelling took things off-screen while they were working on "Beverly Hills, 90210" but the details are up for debate. While Tori says that they were definitely an item, Brian remembers things as just a summer hookup.

"Brian Austin Green, I mean David and Donna, we were on camera together and we are off camera, something. He and I have different perspectives of what that was...It's so funny, because to me, I was like, 'Remember that summer we were together? You said 'I love you' and I said 'I love you.' And he remembers none of that. He was like, 'No, we hooked up. We were friends.' And I was like, 'Cool, OK.' Even now I'm like, 'OK, cool,'" Tori said on "Woman on Top" podcast.

4. Miley Cyrus & Lucas Till

Miley Cyrus and her "Hannah Montana Movie" co-star Lucas Till were an item both on and off-screen. While promoting the film, Lucas revealed that he and Miley had dated for about two months while they were working together.

"Yes, I did [date her]. During the duration of the movie...I think it will make the movie a little better cause it was definitely real," Lucas told Star 94FM.

5. Kaley Cuoco & Johnny Galecki

"Big Bang Theory" co-stars Kaley Cuoco and Johnny Galecki dated both on and off the small screen. The duo coupled up secretly for two years without going public and only dropped the news after they had already split.

"It was such a huge part of my life and no one knew about it. It was a wonderful relationship, but we never spoke a word about it and never went anywhere together...We were so protective of ourselves and the show and didn't want anything to ruin that. But that also made it sad, too. That's not the kind of relationship I want -- I don't want to be hiding," Kaley told CBS Watch! magazine.

6. Vanessa Hudgens & Josh Hutcherson

Vanessa Hudgens and Josh Hutcherson may have been secretly dating while filming "Journey 2: The Mysterious Island" but they ended up getting called out in an interview while promoting the film! During an appearance on the Australian morning show, the hosts mistakenly assumed the duo were dating and asked how long they had been going out for. Josh had to awkwardly clear things up and let them know he wasn't dating Vanessa, although they had been at one point.

"We're not. We were at one point, but she broke my heart…no, I'm just kidding," Josh jokingly said.

7. Mario Lopez & Tiffani Thiessen

"Saved By The Bell" stars Mario Lopez and Tiffani Thiessen were a couple both on their show and in real life. Mario made the revelation in his memoir "Just Between Us" many years later, sharing that the couple "went to movies, went out to eat, hung out at parties, danced together."

The duo eventually called it quits when Mario realized he wasn't ready for that commitment at his age. "I thought that being loyal to Tiffani was the right thing to do. But I can't say that I was capable at that age of following through on my noble intentions," Mario wrote.

8. Nina Dobrev & Ian Somerhalder

Nina Dobrev and Ian Somerhalder's romance wasn't exactly a secret but the "Vampire Diaries" co-stars did keep things under wraps for an entire year before going public with their relationship. Nina says that the duo actually didn't even act on their feelings for a long time before finally deciding they should give things a chance.

"I didn't want to be dating one of my costars -- my goal on the show was to be professional. But sometimes you can't help who you have a connection with, and you can only fight it for so long -- which I did for a really, really long time," Nina told Seventeen.

9. Maureen McCormick & Barry Williams

Maureen McCormick and Barry Williams played siblings on "The Brady Bunch" but they actually were briefly a couple in real life. He didn't confirm the relationship until 39 years after the show wrapped.

"Yes we did [date]. Definitely. I was her first kiss and that was in Hawaii while we were filming those episodes. We snuck away, it was a full moon, we walked along the sand. Well, I knew where that was headed...Of course I set it up!" Barry revealed on a Where Are They Now segment of "The Oprah Show."

10. Matthew Broderick & Jennifer Grey

Matthew Broderick and Jennifer Grey played siblings while they were filming "Ferris Bueller's Day Off" but no one knew they were secretly dating. In fact, they actually got engaged before the film wrapped, without any of the cast and crew knowing they were together. Their relationship finally became public knowledge following a tragic car accident during a vacation in Ireland that made headlines.

"It started while we made the film. It was tricky because it was a secret. No one knew," Jennifer said in the memoir "You Couldn't Ignore Me If You Tried."