Katy Perry is reportedly dating CAA agent Michael Kives.

The 28-year-old singer - who has been single since splitting from John Mayer earlier this year - has started a relationship with her longtime friend Michael, 35.

A source told America's Star magazine: ''Katy and Michael have been hooking up. They were friends first, but Katy leaned on Michael for emotional support after her breakup with John. It's more of a sexual thing for her rather than a heavy-duty relationship.

''She is still calling John because she can't let go. And he still reaches out to her too because he loves to string his exes along.''

While Katy wants a casual fling, Michael - who previously dated 'Charmed' actress Alyssa Milano - is said to be hoping it will develop into something more serious.

The insider added: ''Michael is having a blast with her. He's been bragging to all his friends about Katy, and he's holding out hope that she will want to get serious. He would love for her to be The One.''