ESCANDALO! Kristen Stewart took her lip biting to someone else’s bed according to Us Weekly. Girl better run because the Twihards are super pissed! She is going to wake up with the severed head of a unicorn in her bed for cheating on the magical beast that is Robert Pattinson.

The tabloid claims that KStew hooked up with her married ‘Snow White and the Huntsman’ director, Rupert Sanders. It was a onetime thing, but she is having a wicked case of regret over the ordeal.

“Kristen is absolutely devastated,” a source tells People. “It was a mistake and a complete lapse in judgment.” Us Weekly has also plastered a photo of Stewart and Sanders on its cover that would indicate the two had a romantic relationship.

As for the legions of fangirls who have all pledged their virginity to Rob -they are taking to Twitter to voice their fury…

“mindlesss_Xo: OH HELLLLL NO. KRISTEN STEWART CHEATED ON MAH BEW WITH SOME DIRECTOR. SHE’S SUPPOSED TO BE GOOD TO ROBERT PATTINSON, his luscious self.”

“katieplott: yesssssss the day has come where KRISTEN STEWARTCHEATED ON ROB PATTINSON!!!!!!!! MoVe OvEr KsTeW iT’z My TuRn NoW!!!”

“pierreboobier: sobs why couldn’t kristen stewart cheat on rpattz with me”

The reports go on to insist that Pattinson is “so in love” with Kristen that he is willing to be a doormat and forgive her indiscretion.

What do you think? If she cheated does she deserve another chance?