Clash Of The Costars! 'The O.C' Alums Mischa Barton & Rachel Bilson 'Never Got On Well,' Spills Insider

Barton recently revealed in an interview her reasonings for leaving the show. One had to do with working long hours, but the biggest thing for the star was the bullying and invasion of her day-to-day lifestyle.

Barton’s character was only around for around 3 seasons. Her character was killed off so that she could leave the show.

"There’s resentment that goes back to the show, when Mischa was the more popular one," says the insider, noting that her It Girl status "didn’t sit well" with Bilson.

Bilson was added onto the show as a regular after season 1, and the rest of the cast’s pay had to be evened out, according to Barton. 

In May, Barton, 35, seemed to diss her former castmate when she said things got more difficult in season 2 of the hit series, after Bilson’s "last-minute" promotion. "She was pretty steamed," the source says of Bilson, 39, who hit back on her Welcome to the OC, B**ches! podcast.

While Barton said there were people on set that were very "mean" to her, Bilson claimed she didn’t know "who or what she was referring to." Bilson explained that she did not actually get added last minute to the show.

She insists that Barton’s statement is a complete lie and that’s why the rest of Barton’s claims are doubtfully true. Bilson dismissed Barton’s claims that her title bump was a surprise and said she was "confused" by her claims of being bullied on set. "The gloves are off," adds the insider, "and you can expect the badmouthing to continue."