Katy Perry and John Mayer have reportedly called it quits for the second time.
"It's sad," a source tells Us Weekly magazine, before emphasizing that it may not be permanent. "It's not over until it's over. You have to see how things play out."
"She's leaving the window open," another source said. "They have both been so focused on work."
Perry and Mayer began dating back in the summer and 2012, but split in August of the same year. They got back together a month later.
The two have remained pretty tight lipped about their relationship, but have let out little hints over the time period about their love life.
"I'm very happy in all aspects of my life," Mayer told 60 Minutes back in Jan.
The source of their breakup seems to be their busy schedules. Perry is recording her third studio album and Mayer is preparing for upcoming tour dates and a live Google Hangout.