Mischa Barton was only 17 when she made her debut as Marissa Cooper on The O.C. The rest of the cast was several years older, including her costar and onscreen love interest, Ben McKenzie, who was 25 at the time. However, it turns out the two dated behind the scenes during the show’s first season.

In an appearance on the Wednesday, February 21, episode of the “Call Her Daddy” podcast, Mischa, 38, said that her relationship with Ben, 45, was her “first” and ​that she “had no idea what [she] was doing.”

“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, these things happen, but it was … we threw ourselves all into it very fast,” the actress added.

However, time on the set became more complicated after she and Ben broke up.

“I felt overwhelmed and not ready for any of that,” Mischa said. “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.”

The relationship and subsequent breakup between Mischa and Ben seemed to overwhelm the Spree star.

“That’s in the very beginning of the show before we’re even halfway through a season,” Mischa recalled, referencing ​the timeline of her relationship with Ben. “So there was a lot going on there. That show … so much happened in three seasons.”

Mischa Barton during the Mon Cheri Hosts Barbara Tag at Isarpost
Hannes Magerstaedt / Getty Images

Plus, with Mischa being the youngest member of the main cast from The O.C., the age difference between her and her costars presented a challenge.

“It was kind of complicated for me. I went into that a virgin, a kid, really feeling like I needed to grow up quickly.” Mischa continued. “Acting with people older than me was a bit like, ‘Oh wow. They know what they’re doing. 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.”

Mischa added that she “felt like I needed to catch up, I think, a lot of the time.”

“I was experiencing all my firsts and I was so young and my mom would be on set and ​… I just needed a lot more attention in that sense,” The Ring star admitted. “It was a lot of my firsts, let’s put it like that. And that kind of really separated me, a little, from them, in the sense that I wasn’t out there living on my own in L.A. yet.”

Have a tip? Send it to us! Email In Touch at contact@intouchweekly.com.