Commence musical quibbling! Katy Perry may pen John Mayer song

Katy Perry might be penning a breakup song about her ex John Mayer, and Mayer seems to be taking that prospect in stride.

The “Wildfire” crooner, 36, famously took a lashing on ex Taylor Swift’s track “Dear John” and rebutted with his song “Paper Doll.”

But now, Perry, 29, from whom he split in February, might be trying her hand at the lyrical blast.

“There’s no bad blood,” the “Dark Horse” songstress told Cosmopolitan. “But I’m sure there will be inspired songs.”

Mayer’s response? Been there, done that.

“I have super strength for gang-ups. I’m fine, I’m fine,” the crooner told TMZ on Tuesday. “That’s what you’re supposed to do, man. You’re supposed to write songs. You’re just not supposed to tell everybody you’re doing it.”

And the perennial playboy joked that he’s actually supportive of that kind musical expression and its success on the charts.

“I actually want everybody’s song to go No. 1,” he quipped. “I actually purposely stopped writing hits to give other people a chance to have No. 1 songs. I just stand to the side.”

The former aww-inducing lovebirds collaborated on the duet “Who You Love” from his “Paradise Valley” album last year and publicly gushed about working together on the track — and their relationship — in December.

They reportedly called it quits for the second time in February and reports out Tuesday suggested that Perry might have moved on. She is said to have rekindled her romance with Florence + the Machine guitarist Rob Ackroyd, according to E! News.

The “Roar” singer and guitarist were spotted getting cozy in London on Saturday after the U.K. leg of her Prismatic World tour.

“Katy and Rob are very close and have remained close since they broke up a while ago. Rob has been in London for a while now,” a source told the site.