Robert Pattinson
Actor Robert Pattinson at the 70th annual Golden Globe Awards in January 2013. Reuters

Sorry, Kristen, but Rob has moved on to a different brunette.

Following reports that Kristen Stewart allegedly cheated not once but twice on her former boyfriend and "Twilight" co-star Robert Pattinson, Radar Online reported Monday that Pattinson has officially moved on. According to a report, the 27-year-old British native was spotted with a mystery brunette in Los Angeles this past weekend.

Allegedly, Pattinson attended an L.A. house party with the unidentified female Saturday night, showing her off at actress Shoshana Bush's birthday celebration. According to the report, eyewitnesses claim Pattinson was spotted "holding hands" and "kissing" his rumored love interest.

"Rob and the brunette turned up around midnight. They were cute together," said a source, who described Pattinson's mystery girlfriend as "a girl next door" type and "very sweet." "At one point, he was talking to someone and she wandered over and grabbed his hand and pulled him over to near the pool. Their hands were all over each other!" the source later added.

Last week OK! magazine published claims that Pattinson's girlfriend of three years and former on-screen love interest Kristen Stewart cheated on Pattinson twice with her "Snow White and the Huntsman" director, Rupert Sanders. One day prior, RealEstalker confirmed that Pattinson had put the Los Feliz, Calif., home he'd shared with Stewart on the market for $6.75 million.

This isn't the first time Pattinson has been spotted with a "mystery woman" following his split from Stewart earlier this year. In July the Daily Mail obtained photos of the "Maps to the Stars" actor driving with an unidentified female later confirmed to be model and actress Riley Keough. Despite multiple reports claiming the two were an item, a rep for Keough denied any romantic ties.