For the second time in less than a year, Katy Perry and John Mayer have pulled the plug on their long troubled relationship.

E! Online reports no pubic reason has been given for the latest split, but given the couple's volatile history, the breakup comes as no great surprise. In times past, they have cited everything from trust issues to schedule conflicts for their separations. 

Back in March of this year, the two split over what was reported to be Perry's insecurities and Mayer's resentment over the lack of attention he was receiving.

Back then, a source told Radar Online, "Katy and John reconnected once she had a break in her Prismatic World Tour. So, for those few months they had a great time, pretending that it would last -- and of course it didn't."

More recently, Perry's schedule has only seemed to grow more cluttered. The "Roar" singer performed a magic show in Los Angeles on July 22 to promote her latest perfume, Mad Potion.

Overall, the Daily Mail reports the most recent split marks the fourth time the 37-year-old Mayer and the 30-year-old Perry have gone their separate ways. News of the breakup comes just three weeks after the pair spent the July 4 holiday weekend together in Chicago, where they were spotted attending the Grateful Dead farewell concert at Soldier Field and described as looking "very much together."

In 2013, the pair famously released the PDA-filled duet "Who You Love."

A seven-time Grammy winner, Mayer has previously dated such celebs as Taylor Swift, Jennifer Aniston, Jessica Simpson, Jennifer Love Hewitt, and Minka Kelly.  Meanwhile, Perry, a 13-time Grammy's nominee, infamously split with then husband Russell Brand after be "blindsided" her with divorce papers.

Currently, Mayer has no tours scheduled and last publicly performed in June at Terrapin Crossroads in San Rafael.