AceShowbiz - Actress Rachel Bilson still feels a tinge of jealousy watching her ex-boyfriend Adam Brody kiss their "The O.C." co-star Samaire Armstrong on the set of the teen drama series.

Bilson and Brody played on/off couple Summer Roberts and Seth Cohen for much of "The O.C.", and their chemistry spilled over into real life with the pair dating from 2003 to 2006.

However, the onscreen romance was complicated in season one with the introduction of Armstrong's character Anna Stern, who, in the episode titled "The Homecoming", makes a move on Seth and locks lips with him in his bedroom.

Bilson recently revisited the storyline for her podcast, "Welcome to the OC, B**ches!", and admits she still experiences some strong feelings about the TV love triangle.

"When Seth is in the bedroom with Anna and she goes to kiss him, I see Samaire like, slip tongue," Bilson revealed on the latest episode of her podcast, which she co-hosts with her former co-star Melinda Clarke.

"I get transported back to 18 years ago and I get a little jealous," she confessed. "It was like the real-life (love) triangle playing out as I'm watching it."

Bilson admits the onscreen action actually caused some "tension" between herself and Armstrong when the cameras weren't rolling.

She added, "I feel like it definitely played out a little bit in real life for a minute... even though not really really, but I remember the tension with Samaire and I like, a little bit."

Bilson went on to date her "Jumper" co-star Hayden Christensen, the father of her six-year-old daughter, Briar Rose. The couple, who was once engaged, separated in 2017.

Meanwhile, Brody is happily married to "Gossip Girl" actress Leighton Meester, with whom he shares a five-year-old daughter and a baby son, who was born last year (20).