They both sing the hell out of the song, but that physical distance between them is the main attraction: The song only works if you truly believe that they can’t stand to be even six feet away from each other. When they finally do walk down their respective staircases and take center stage and risk any sort of proximity, it’s an electric moment whether you believe all the rumors or not. Monica sings, “Not yours.” Brandy sings, “But mine.” You decide what they’re really saying.
