Kristen Stewart 'cheats on Robert Pattinson with married Snow White And The Huntsman director Rupert Sanders'

R-Patz hinted at marriage: 'Kristen has always done something to me'
British director has two young children with model Liberty Ross

PUBLISHED: 19:55 EST, 24 July 2012 | UPDATED: 20:27 EST, 24 July 2012

Kristen Stewart has reportedly cheated on Robert Pattinson with a married filmmaker twice her age.

The Twilight actress, 22, is said to have fallen for the charms of Snow White And The Huntsman director, Rupert Sanders, 41.

As Kristen prepared to spread her wings from the vampire franchise, she joined forces with the father-of-two to work on his $ 170m feature debut - which was released just last month.

The not-so-happy couple? Kristen Stewart is alleged to have cheated on Robert Pattinson with married director Rupert Sanders

But despite the film long since wrapping, it has been reported that just last Tuesday, Kristen was caught in the arms of Rupert - with Us Weekly claiming to have photographic evidence.

Kristen and Robert were hailed as the perfect couple, in love both on and off screen.

However, it seems not even they are immune to the perils of infidelity claims.

Proof? Us Weekly claim their is photographic evidence

Proof? Us Weekly claim to have evidence

A source told Us Weekly that Kristen and Rupert, who is married to British Vogue model Liberty Ross - were caught in a romantic clinch and it seemed like 'they couldn't get enough'.

The insider added: 'Kristen is absolutely devastated. It was a mistake and a 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. She's a good person who just made a bad choice.'

While it is not known exactly how long the Twilight pair have been dating, due to their extreme privacy at the beginning of their romance, R-Patz, 26, finally came clean at the BAFTAs in February 2010.

Just days ago, the duo looked happy at Comic-Con as they promoted the final film of their franchise, The Twilight Saga: Breaking Dawn: Part 2, and also at the Teen Choice Awards on Sunday.

The news will come as a shock after British actor Pattinson hinted he wanted to marry K-Stew.

Speaking to BlackBook, he explained: 'There was a magazine, with these pictures, saying I was getting married. No one ever knows what is true or what isn't.

'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.'

Mail Online is awaiting comments from both Robert and Kristen's representatives.