One of the steadiest showbiz couples have been rocked by reports of cheating.
Kristen Stewart has reportedly cheated on Robert Pattinson with the married director of her latest film Snow White And The Huntsman, Rupert Sanders, according to Us Weekly.
The American mag claims to have obtained photographic evidence of the pair caught in a series of steamy rendezvous earlier this month.
According one photographer who saw them kissing, "it seemed like they couldn't get enough".
A source told also People.com that the actress is "devastated", but claims she and Rupert were not having a full blown affair.
"It was just a fleeting moment that shouldn't have happened. She never meant to hurt anyone. She's a good person who just made a bad choice."
Rupert is married to British Vogue model Liberty Ross, with whom he shares two children, while Kristen has been with Robert since they met on the set of Twilight in 2008, although they didn't confirm their romance until February 2010.
The news comes as a shock after only two weeks ago, the pair were forced to deny rumours they were set to wed.
Speaking to BlackBook, Robert did hint that a wedding may be on the cards later down the line.
"There was a magazine, with these pictures, saying I was getting married. No one ever knows what is true or what isn’t," he said.
"Even my own mum called to ask me if it was true. It’s not. At least, not yet. But it is true that Kristen has always done something to me that others haven’t."
Representatives for both Kristen and Rupert have so far had no comment.
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