Seems like John Mayer has a thing for the young ladies...last year he was rumoured to be hooking up with the then 20 year old Taylor Swift, and now he's gone even younger, apparently hooking up with 18 year old Miley Cyrus at the Grammys!

But according to Star magazine, it was Miley who did most of the ground work! Apparently the teenager was following Mayer around "like a puppy dog" all night at Clive Davis' pre-Grammy party.

An eyewitness told the magazine, "She put her arm around his waist, and even grabbed his behind", and apparently Mayer was more than happy to "reciprocate."

"Things got even hotter between them the following evening at the Grammys," says another source.

Apparently the pair were busted having a massive pash session, "It was quick and intense and a bit shocking, but it also seemed sweet," says the eyewitness. "Afterward, Miley slapped his butt and told him, 'You rock!'"