Kristen Stewart has cheated on Robert Pattinson with a married filmmaker twice her age, it has been claimed.
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.
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.
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’.
And an insider told People.com: ‘Kristen is absolutely devastated. It was a mistake and a complete lapse in judgement. 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.’
Insiders have made the allegations to both Us Weekly and trusted celebrity website People.com.
Kristen’s alleged infidelity came just months after Robert gave an interview to Italian Vanity Fair magazine saying that he has ‘never understood’ people who cheat.
He said: ‘There is one thing I’ve never understood: Why people cheat. My parents met when my mom was 17 and my father 25, they are still together, and seem very happy.
‘I grew up believing that you can be together all of your life.’
While it is not known exactly how long the Twilight pair have been dating, due to their extreme privacy at the start their romance, R-Patz finally came clean at the BAFTAs ceremony in February 2010.
At the time, the 26-year-old told The Sun: ‘It is extremely difficult but we are together, yes. We can’t arrive at the same time because of the fans. It goes crazy.
‘This was supposed to be a public appearance as a couple but it’s impossible. We are here together and it’s a public event but it’s not easy. We have to do all this stuff to avoid attention.’
Just days ago, the duo looked happy at Comic-Con as they promoted the final film of their franchise, 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.’
And in her most recent interview, with the June issue of Elle magazine, Kristen said she was getting tired of her ‘boring’ life, and wanted something ‘bad’ to happen to her.
She said: ‘You can learn so much from bad things. I feel boring. I feel like, “Why is everything so easy for me?” I can’t wait for something crazy to f***ing happen to me. Just life.
‘I want someone to f**k me over! Do you know what I mean?’
Meanwhile, Rupert’s wife Liberty, 33, rather cryptically retweeted a quote from Marilyn Monroe, saying: ‘Sometimes good things fall apart so better things can fall together.’
She later followed this with another retweet, this time quoting American author and poet Maya Angelou, saying: ‘If you find it in your heart to care for somebody else, you will have succeeded.’
Liberty, who is credited on IMDB as Queen Eleanor in the Huntsman, then simply wrote: ‘WOW’.
Following her tweets, Liberty appeared to have deleted her Twitter account.
When Kristen signed up to play Snow White in Huntsman, many thought that it would mark a new stage in her career following her role as Bella Swan in Twilight.
And speaking about his lead actress in the role at one of the movie’s premieres last month, Rupert said he was thrilled by her performance.
He told E! News: ‘She’s got a great spirit, she’s really quite rebellious…and feisty and kind of wild. And that’s really what I wanted the modern Snow White to have.
‘I didn’t want her to be timid and I didn’t want her to be frightened and relying on men, you know.
‘She’s very strong and very driven, and I think that’s true in her personal life…She’s got a big weight of the world on her shoulders and she carries it incredibly well.’
Snow White And The Huntsman marks the first major motion picture that Rupert directed – but he has already signed on to take the helm of the sequel, according to IMDB.com.
It is believed that Huntsman was the first in a planned trilogy of movies about the modern Snow White.
Prior to the film, Rupert had made a name for himself directing commercials.
Following the infidelity claims breaking, Kristen is already facing backlash from fans of the tween favorite couple.
One fan said: ‘HOW COULD SHE? Rob loves her so much.’
Another told HollywoodLife.com: ‘Ever since she did Snow White And The Huntsman she changed. She’s more Hollywood now. More into her looks. I mean how many magazine covers she done in the past few months? I lost count.’
Others took to Twitter to voice their disappointment in the actress, with one tweeting: ‘ OH HELLLLL NO. KRISTEN STEWART CHEATED ON MAH BEW WITH SOME DIRECTOR. SHE’S SUPPOSED TO BE GOOD TO ROBERT PATTINSON, his luscious self.’
And another added: ‘Kristen Stewart, how could you cheat on Robert Pattinson with a married man that has children? So disappointed in you.’
In a bid to lose her wholesome image, Kristen also played the role of Emily in Adventureland in 2009.
The cheeky actress, who has disrobed for her latest project On The Road, engaged in sexual scenes with Ryan Reynolds, who played the married park’s maintenance man.
MailOnline is awaiting comments from Kristen’s representatives.