Katy Perry 'Flipped Out' Over BFF Rihanna Recording Duet With Ex John Mayer ... Entertainmentwise Katy Perry and Rihanna falling out about a boy, surely not? Well yes that's what the latest report out there claims with allegations the Prism babe flipped out when Ri revealed she wanted to duet with John Mayer. Mayer of course is Perry's on/off ex and despite ... |