Katy Perry ‘put brakes on Mayer romance’

Katy Perry was apparently responsible for "putting the brakes" on her fledgling romance with John Mayer.

It has been reported that the stars have cooled down their budding relationship after John decided he didn't want a girlfriend. Now it has been claimed that Katy is the one calling the shots.

Katy was apparently worried about falling for the musician, who has a reputation as a Hollywood heartbreaker after dating a string of stars including Jennifer Aniston and Jessica Simpson.

"She's putting the brakes on and is limiting their dates," a source told UK magazine Closer.

Meanwhile, one of John's famous exes apparently warned Katy not to get too involved with the musician.

Taylor Swift - who once dated John and reportedly wrote break-up song Dear John about him – is believed to have expressed her concerns for the newly divorced brunette beauty.

"Taylor's told Katy not to get entangled with John because he treated her badly. But Katy says he'd grown up a lot since then - it's just moving too fast," the insider added.