They break up! John Mayer and Jessica Simpson, one of the most unlikely couples of the year, recently split up, and it was John Mayer who made the move.

The source told the site, “They officially called it quits this past weekend. They’d been having problems for a while now and just decided it’d be better to end things.” As reported in Pop Tarts Thursday, it may hve been Simpson’s jealous instincts that led to the couple’s demise. After seeing Mayer getting a little too close to Giorgio Armani’s niece, Roberta, last week at the Costume Institute Gala, Simpson became enraged, says the Australian magazine Famous.

A source who witnessed the scene revealed to the magazine, “Jess barked in his ear and John just sighed and put his hand up to his head. Later he tried to grab her hand, but it was clear she was upset with him.”

Before getting into another relationship, Jess may want to work on some of her insecurities, according to close sources. Says one, Jessica has an inferiority complex when it comes to her sister, Ashlee, especially Ashlee’s young, more desirable age. When John saw a picture of Ashlee and asked how old Jess was when it was taken, Jessica became upset. According to the source, “He definitely touched a nerve.”