Rumor Mill: Justin Timberlake steps out on Jessica Biel, according to Us Weekly

Breaking breathless news: Justin Timberlake cheated on girlfriend Jessica Biel with the almost interchangeable Olivia Munn in September. At least according to Us Weekly.

In the latest issue, Us reports that Timberlake and Munn, a "Daily Show" correspondent, met at a MySpace event (yes, apparently MySpace still exists and has the money to throw lavish Manhattan parties that attract the likes of Justin Timberlake and Olivia Munn), proving once and for all that social networking is merely an elaborate ruse designed to assist superstars in cheating on their actress/model girlfriends.

Apparently the two met, hit it off and exchanged phone numbers. This is where Us's report veers into sordid territory:

Munn resisted [Timberlake's] advances, telling him it was a no-go if he was still with Biel, 28, the source tells Us Weekly. But Timberlake "has been telling people it’s over with Jessica, even though "the reality is he's just doing it behind her back."

Believing he had left Biel and that her relationship with Timberlake might develop into something serious, Munn took him to her hotel, the Gansevoort Park Avenue NYC, Sept. 27 and 28, where "they were openly affectionate," the insider adds.

The insider tells Us the two "had amazing sex" that night.

Would you expect anything less from this guy?

It should be noted that a rep for Justin Timberlake denies the story and Munn has refused to comment.

Source: Us