Why Kristen Stewart Dropped Out of 'Cali'; Amber Heard, Carey Mulligan Eyed as Replacement (EXCLUSIVE DETAILS)
"She is so distraught over Rob that she can't focus on anything but getting him back," the source, who asked not to be identified but was briefed on her decision, said Thursday.
"She can't bare to be without Rob."
In doing so, Stewart -- who in July was caught cheating on Pattinson with Snow White and the Huntsman director Rupert Sanders -- has put those still involved with Cali in a major bind, the source revealed.
After the jump, get the scoop on who's in the running to replace Stewart.
The reason: Stewart had spent the past few months working as a producer on the project, which allowed her to oversee the selection of its director (Cassavetes) and her co-star (Alex Pettyfer). Both Cassavetes and Pettyfer were said to have turned down other projects to work with Stewart, according to the source.
"Everyone has been so understanding of her current situation," the source said. "Despite film scheduling and budget, [they were] willing to give her the time necessary to recover from the media storm.
"But it doesn't seem to matter. She's lost all interest in work and the projects that she was so passionate about just two weeks ago. Even though everyone has been pulling for her and trying to encourage her to stay on, the star's main focus remains on Rob and what she can do to get him back."
As of Thursday, some of Hollywood's biggest names have been mentioned as possible replacements for Stewart, including Amber Heart (The Rum Diary) and Oscar-nominated beauty Carey Mulligan (An Education; The Great Gatsby). The film, about a couple who comes out of hiding to save the girlfriend's sister, is supposed to hit theaters next year.
On July 25, the same day that US Weekly released photos exposing her affair with Sanders, Stewart released a statement apologizing for her actions.
"I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected," Stewart said. "This momentary indiscretion has jeopardized the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I'm so sorry."
In wake of the scandal, Pattinson, 26, is said to have moved out of the home the couple shared in Los Angeles. After keeping a low profile over the last couple of weeks, he's expected to make his first public appearance Monday on The Daily Show.
He'll follow with an appearance on Tuesday's Good Morning America.