It was life imitating art on The O.C.set, according to star Rachel Bilson.

The actress, who played Summer Roberts on the teen drama, said the onscreen love triangle spilled over into real life, resulting in "tension" between her and costar Samaire Armstrong. In the series, Armstrong's character Anna Stern dates Adam Brody's Seth Cohen, who's actually in love with Summer. Meanwhile, Brody and Bilson dated in real life for three years during the show's run.