05/20/2012 at 11:00 AM EDT
Is Katy Perry
trying to send a message to Russell Brand?
The singer, whose divorce from Brand
is supposed to be finalized next month, is set to sing a revealing breakup song, "Wide Awake" off her latest album, this Sunday at The Billboard Music Awards in Las Vegas, PEOPLE has learned.
"It's obviously about Russell," a source said, though Perry has not publicly confirmed it.
The song speaks about being blinded by love, including the lyrics, "I wish I knew then what I know now – wouldn't dive in, wouldn't bow down."
Perry has since moved on from Brand and is seeing
Florence and The Machine guitarist Robert Ackroyd.
The Billboard Music Awards air Sunday on ABC.