When: July 2012-Present

John sure does have a thing for musicians, doesn't he? Actually, what are we talking about? He'd probably have dated Katy Perry if she worked as an Arby's fry cook in south Jersey. John Mayer just likes hot chicks, and we can't fault him for that.

Perry is Mayer's most recent hook-up and the two have been spotted everywhere together—from candle-lit dinners, to drinks at the Chateau Marmont, to swanky pool parties.

Smash Probability: She's his summer fling. You'd get as much as you can done, too, if you only had three months.