7. Justin Timberlake  

While it's tough to believe any man could step out on the preternaturally lovely Jessica Biel, gossip mags claimed Justin Timberlake did just that in 2010. The multi-talented performer is alleged to have seduced actress Olivia Munn with promises that he was no longer with Biel. {relatedarticles}The scandalous three-day affair was a flash in the pants. While Biel and Timberlake called it quits for a brief stint, they eventually reunited and got hitched in 2012. Munn is said to have felt regretful about the fair-weather fling.