John Mayer reportedly "made Katy Perry his conquest".
The couple are rumoured to be dating following Katy's high profile divorce from British comedian Russell Brand.
Ladies' man John has a history of dating gorgeous celebrities and moving on to the next beautiful lady swiftly.
Apparently John is no longer interested in fostering a romance with Katy after dating for about a month.
"John did a real number on Katy," a source told Radar Online.
"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."
The tension between the pair was palpable at their mutual friend's dinner party Tuesday night.
"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," an eyewitness detailed.
"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."
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