There’s something about the scent of unwashed hair, Valtrex ointment and Massengil that Katy Perry can’t resist, because she started dating John Mayer shortly after divorcing her husband of less than a year Russell Brand, and surprise! — it did not end well. Radar Online says:

“John did a real number on Katy,” a source [revealed]. “He laid on the charm thick and promised her he was a changed man. She fell head over heels for him and then once he had made his conquest, he dumped her.”

Meanwhile, there appears to be no love lost between Mayer and Perry. A source spotted the former couple at a mutual friend’s dinner party on Tuesday night and they completely ignored each other!

“Katy stayed in one room the whole night and John stayed in the other and when they passed each other they both just kept their head’s down… they had this incredible animosity for each other and everyone else at the party could feel it,” an eyewitness said.

I’m no Katy Perry fan, but I hate this smarmy little prick. And I do mean HATE. He’s like the white Kanye West. He’s got all the charm and savoir faire of yeast infection.

This Borsalino hat is slightly less gay than John Mayer’s, plus it’s made out of hemp. Advantage: Borsalino.

At the Magic House Party in Malibu earlier this month:

PHOTO CREDIT: Pacific Coast News