Prince William & Kate Middleton back on?

Prince William and former girlfriend Kate Middleton have resumed their relationship, PEOPLE reports

The two, both 25, attended a party earlier this month at an army barracks where William is posted as an army officer, say the reports.

William has invited Middleton, to the Concert for Diana, in memory of his mother, scheduled for London's Wembley Stadium next Sunday, the Mail on Sunday reports.

The paper also claims the couple kissed at the June 9 army party, and that Middleton will spend time with William, his brother Harry and Harry's girlfriend, Chelsy Davy, backstage at the Diana concert.