Katy Perry and John Mayer Split

Katy Perry and John Mayer have decided to end their relationship for the second time after calling it quits in August and then reconciling in September and continuing to date for the past seven months. "It's sad," a friend of the couple tells Us Weekly, who first broke the story. "It's not over until it's over," another source tells Us. "You have to see how things play out. She's leaving the window open. They have both been so focused on work."