SPLIT! John Mayer Dumps Katy Perry! 4

So much for Katy Perry and John Mayer‘s budding romance: John has ended the relationship, which kicked off a few weeks ago.

“John did a real number on Katy,” a source tells RadarOnline.com. “She held off from his advances for the longest time, but he laid on the charm thick and promised her he was a changed man. She eventually gave in, fell head over heels for him and then – yep – once he had made his conquest, he dumped her.”

And they’re no longer on friendly terms, according to the Web site. A source says the newly-minted exes both attended a mutual friend’s dinner party Tuesday night, but ignored each other.

“It was so weird! 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,” says an eyewitness. “It was like they had this incredible animosity for each other and everyone else at the party could feel it. You could cut the atmosphere with a knife. It was all incredibly high school!”