Sandra Bullock's boyfriend Bryan Randall is allegedly cheating on the "Gravity" star with his ex-girlfriend.

According to OK! magazine, as shared by Celebrity Dirty Laundry, Sandra Bullock shouldn't be surprised about Bryan Randall cheating because she was warned beforehand by her friends.

"Bryan kept Paris in the picture as a back-up plan, and now he is trying to cover his tracks," the insider claimed.

"Paris's social media pages don't jive with Bryan's break-up story though. Bryan insists that he and Paris were long over when he met Bullock in May, but Paris was posting selfies of herself with Bryan Randall on Instagram this Spring, AFTER Louis's birthday party," the article said.

The article added that Sandra Bullock's boyfriend has been seeing her and Paris St. John when the fashion photographer started dating the "Gravity" star back in May.

However, Sandra Bullock won't heed to her friends' advice because she's head over heels in love with Bryan Randall.

This is not the first time Star raised the red flag on Sandra Bullock's boyfriend.

According to Star magazine, as shared by Hollywood Life, apart from cheating, the former model was already arrested multiple times and he also had a problem controlling his alcohol addiction and temper.

"Although Bryan's rowdy behavior reportedly began when he was just a young kid, his first major run-in with the law happened in 1988, according to Star," the article said. "That year, Bryan was arrested on a DUI charge in Portland, and during the five years it took him to eventually plead guilty, he got into even more trouble for missing court dates and driving with a suspended license."

Sandra Bullock and boyfriend Bryan Randall were first reported to be dating back in August after they were snapped on a night out in Craig's restaurant in West Hollywood.