According to Star magazine, Bieber had a "night of debauchery" and "drug-fueled" hookup with a nursing student named Milyn Jenson on December 21, alledgedly cheating on Gomez and triggering their split.

Star cites a so-called "insider" as saying that : "Bieber joined Jenson and rapper pal Lil Twist at the Four Seasons in Beverly Hills that evening, before they all allegedly went to buy weed at a smoke shop in Hollywood."

Back at the hotel, says the tabloid's source, the trio "smoked pot" and made the street cocktail "sizzurp."

"The guys poured it into plastic cups and were drinking it throughout the night," alleges the Star source, who goes on to claim that at one point the group got into Bieber's Range Rover to visit the pop star's mansion in Calabasas, with Bieber allegedly driving "like a crazy person" on the way.