Katy Perry and John Mayer's break up stunned many for the couple appeared to be getting serious in settling down. The plans that the two have for their future might be the reasons why the 'Roar' songstress felt remorseful after the split.

Although Katy Perry and John Mayer have chosen to remain silent about their break up, recent reports claimed that the brunette beauty couldn't help but trash talk the 'You're Body Is a Wonderland' crooner who allegedly cheated on her. The difference is, Perry does the trash talking only when she's with her closest friends.

"She's letting rip, big time. Everything from his over-the-top metrosexuality - the waxing, the man-scara, the cashmere cardigans - right through to the size of his manhood," claimed one insider to Heat magazine.

The 29-year-old pop star reportedly doesn't feel hesitation whenever she talks about her former beau's flaws: "Katy's pulling no punches in trash talking him. And frankly, he deserves it for what he did and the lies he told her - wanting to get married while carrying on with other women behind her back."

Katy Perry and John Mayer break up is also difficult for they have recorded one song together. Knowing that there's a possibility that Mayer will go back to his old ways, Perry reportedly depends on hypnotherapy to make sure that she won't take Mayer back if he asks for another chance.

"Katy was devastated when they broke up. But Katy is a firm believer in alternative therapies and she wants to wipe him from her life for good, so she decided to see a hypnotherapist. She wants to retrain her brain to prevent John coming back," claimed one source to Grazia magazine.

Though unattached, the 'I Kissed a Girl' songstress is currently being linked to Robert Pattinson.