Perry can't take Mayer's inattentive demeanor and wandering eye any more, with the pair calling it quits over the weekend.

The couple began dating in early August and split after just two weeks. After reconciling a few weeks later, they again split over Mayer failing to meet Perry's high standards.

A source close to the singer said: 'John just can’t commit, and he kept luring Katy back with promises that were 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",' the source reveals.

Mayer was spotted at the SNL after party Saturday night in New York, at the same time Perry was performing at the Hammer Museum gala in Los Angeles.

The split must have come as bitter sweet news to close friends of Firework singer Katy are said to be worried about her falling for the charms of bad boy Mayer so shortly after her failed marriage to Russell Brand.

She apparently took a bit of persuading, but the ladies' man - who has dated the likes of Jessica Simpson and Jennifer Aniston in the past - eventually won her over.