Kristen Stewart Cheated on Robert Pattinson With Married Director?

The dynamic duo of Kristen Stewart and Robert Pattinson may be over due to reports that Stewart cheated on Pattinson with a married director. Stewart and Pattinson have been together for three years after working together on the "Twilight" series.

Stewart and director Rupert Sanders, 41, were photographed hugging and looking rather romantic on July 17, according to reports. The two worked together on "Snow White and the Huntsman" and became involved. Sanders is married to model Liberty Ross, and the couple has two young children.

Now Stewart is allegedly regretting her decision, which a source has told People magazine was "a mistake and complete lapse in judgment. She wasn't having an affair with Rupert. It was just a fleeting moment that shouldn't have happened. She never meant to hurt anyone."

The "Twilight" saga brought Stewart and Pattinson together both on- and off-screen, much to the delight of fans. The two remained rather stoic about their relationship at first but eventually began showing signs of interest and public displays of affection, again making fans happy.

Their careers have skyrocketed since "Twilight," with Stewart taking on roles in "Snow White" and its sequel, as well as the new film "Cali." Pattinson, meanwhile, has appeared in "Water for Elephants" and the upcoming "Mission: Blacklist."

Representatives for Pattinson, Stewart, and Sanders have not released statements yet, but many are wondering whether this is the end of the road for Pattinson and Stewart. It was just days ago that Pattinson denied the couple was getting married anytime soon.

"There was a magazine, with these pictures, saying I was getting married," Pattinson told BlackBook magazine. "Even my own mum called to ask me if it was true. No one ever knows what is true or what isn't."

"I don't talk about my relationships with female friends, not to mention how I don't talk about my relationship with Kristen Stewart, an actress I admire because she's a real person, and a real actress," he told Style magazine last year.