2011 January 14. 19:20

Justin Timberlake Cheated On Jessica Biel With Olivia Munn

It still baffles me when famous people think they can get away with cheating. Hey guys, newsflash: it never works! So goes the tale of Justin Timberlake and Jessica Biel. According to reports, the former N'Sync star has cheated on his longterm galpal Biel with Daily Show correspondent and actress, Olivia Munn.

Justin Timberlake cheated on Jessica Biel with actress Olivia Munnduring a three-day fling this past September, reports the new Us Weekly. Timberlake, 29, and Munn, 30, a Daily Show correspondent who stars in the upcoming NBC series Perfect Couples, first met at a Sept. 26 MySpace event. After exchanging numbers, he "started chasing her immediately," says an insider.

Munn resisted his 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.