According to Star magazine (our favorite source), Justin Timberlake has been cheating on Jessica Biel with Rihanna for the past month or so.

The pair were supposedly spotted grinding at 1Oak’s VMA party in NYC earlier this month. According to sources, they also threw themselves a private after-party in Rihanna’s hotel room after the event.

The pair are currently working on Rihanna’s new album together, where Rihanna has been giving Justin lapdances for fun.

Update: There’s a good chance that Justin wasn’t cheating on Jessica, as US Weekly is now reporting that the couple split about a month ago. According to them, Justin broke off his 3-year relationship by ending things with Jessica on the phone. Jessica is reportedly still in denial about the split.

Update #2: Sources are now saying that Justin and Jessica were out having a romantic dinner on Monday night.