Mischa Barton Confirms She and 'The O.C.' Co-Star Ben McKenzie Had 'Off Screen' Romance, Too

The actress, who was 17 when the series kicked off, said the whole experience was "kind of complicated for her," having to act romantically opposite her 25-year-old co-star as a fresh, young actress.

"I went into that a virgin, a kid, really feeling like I needed to grow up quickly," she said on the latest episode of the Call Her Daddy podcast, saying that she felt like she was playing catch-up with her older colleagues.

"Acting with people older than me was a bit like, 'Oh wow, they know what they're doing,'" she added. "'And there's gonna be relationships on this show and you're gonna need to play that part.' And I didn't feel really ready for that 'cause I was always a really late bloomer in school and I hadn't really dated."

"I just had no idea what I was doing, really," she continued. "I felt like I needed to catch up, I think, a lot of the time."

She added that her being so much younger than her co-stars made things "a bit tricky for everyone," as all of this was so new to her. On top of that, her mom was on set. "I just needed a lot more attention in that sense," she explained.

As for her real-life off-screen relationship with McKenzie, that was a first, too, "and I had no idea what I was doing." TooFab has reached out to Ben McKenzie's representatives for comment.

"I had no idea about relationships at all or sex, so it was kind of just a whole learning curve for me," Barton said of where she was at when she started filming that season. She also revealed she'd lost he virginity during filming on the show, but did not reveal her partner.

"I think that kind of set things off on the wrong foot, too, because it was like, you know, people hook up on these shows and whatever and these things happen, but we threw ourselves all into it very fast," she said.

This revelation is a reversal from what Barton and McKenzie have both said in the past. The pair have either declined to comment on any real-life romance during her three seasons on the show, or outright denied it.

On the podcast, Barton said that the relationship happened within the first half of the first season, with the actress saying it became a whole thing on set.

"I remember they were like, 'Mischa's disappeared with Ben and she's only 17-and-a-half, 18,' and the producers went to my parents and were like -- it was kind of a whole ordeal."

Then, there was the awkwardness after they broke up and had to continue working together ... romantically. Barton's Marissa Cooper enjoyed an on-and-off relationship with McKenzie's Ryan Atwood.

"When you break up, and things don’t work and they see you dating other people," she mused. "Notoriously, there was a lot of inter-dating on that show and different people getting together, but it definitely was tricky that it happened like right out of the gate and that. Like, I felt overwhelmed and not ready for any of that."

Looking back, she actually thinks that the emotional turmoil after their real-life breakup actually helped fuel the intensity of their on-screen chemistry. "I think he was like really angry with me to begin with, and I felt the punishment of that," she said.

She said the producers weren't happy about their young stars attitudes at that time, either, but their chemistry on the screen was undeniable.

"That sexual tension was there, it reads," she said. "Even when you’re looking at the scenes on the Ferris wheel and stuff -- I think we kind of hated each other at that point, but there was still this intense kind of tension there, and so it really worked for the show."

She said that she thinks fans connected with them so much "because there was genuine friendship and love there on some level." Barton would ultimately leave the show after the third season while McKenzie would move on to an on-screen relationship with Autumn Reeser's Taylor Townsend in the show's final season.