Katy Perry has broken up with John Mayer again. The "Part of Me" singer is said to have told the "Half of my Heart" singer to lose her number because he cannot commit.

"John just can't commit, and he kept luring Katy back with promises that was going to change, but then he didn't. Katy was pretty crazy about him, so she kept giving him another chance. John liked Katy, so he wanted to keep her in his life, but it just wasn't up to Katy's standards. She needs the guy to be on board 100 percent and she was sick of John disappearing for five days at a time, then booty calling her, then straightening up and treating her well, only to go back to his old behavior a few days later. Finally she was like 'lose my number,'" a source told Radar Online.

The on-again/off-again couple first began dating in early August but split after just two weeks with friends saying it was only a casual rebound romance following her divorce from Russell. The pair reconciled a few weeks later but this time they have split for good, according to reports.