Pals warn KATY PERRY her secret addiction will END only in tears! JUST two weeks after dumping her badboy lover JOHN MAYER, KATY PERRY had a change of heart and went groveling back to him, say sources.

Now friends of the 27-year-old Grammy-nominated singer – who broke up with Mayer after he told her to go on a diet – fear she’s headed for certain heartbreak with the lusty lothario.

“After they split, Katy had a change of heart and started bombarding John with phone calls, texts and e-mails, begging him to get back together,” a close pal told The ENQUIRER.

“Katy promised this time around she’d be a better girlfriend, even though John is the one who treated her poorly. It’s pathetic.”

The ENQUIRER recently reported that the heartbroken “Firework” singer had been drunk-dialing her ex-husband Russell Brand after her romance with Mayer, 34, collapsed in August.

“Katy has been drowning her sorrows in a sea of booze and partying,” said the pal. “It’s inconceivable that she would take John back, but she’s very vulnerable right now.”

Katy and John were spotted taking in a concert at a Los Angeles music festival on Sept. 1. And three days later they had a romantic dinner date at The Little Door restaurant.

Now, Katy’s friends are worried “she’s headed for a major meltdown,” said the pal.

“Katy has spectacularly bad taste in men, and to her John is the coolest guy around. But the next time he crushes her heart – which is bound to happen soon – it could have devastating consequences for her, both personally and professionally.”