The Celebrity singer has been teasing his new track Without a Fight for the past few days, urging fans to make guesses as to who his mystery duet partner is.
Just before he announced Demi was the mystery collaborator on Thursday (12May16), she added to the suspense by tweeting to Brad, "Reba MCEntire?", to which he replied, "Great guess! But no..."
Brad and Texas native Demi first paired up at the iHeartRadio Music Awards last month (Apr16), when he joined her onstage as she performed Stone Cold.
Without a Fight, the first single from Brad's upcoming 11th studio album, will be released on Friday (13May16).