Nicki Minaj and Mariah Carey are proving to be as combustible of a pair as many bloggers feared—or more likely, hoped. The divas, who will both be judges on the upcoming season of American Idol,were captured arguing in hidden-camera footage posted by TMZ Tuesday. Minaj is shown flying into an expletive-ridden tirade that could’ve been lifted from one of her Parental Advisory–required raps during auditions Tuesday in Charlotte, N.C. “I told them, I’m not f--kin’ putting up with her f--kin’ highness over there,” Minaj shouts, before apparently threatening to “knock out” Carey, who can’t seem to get a word in edgewise. (Watch the video here.) Keith Urban, who joins the duo and Randy Jackson at the judges table, fidgets appropriately uncomfortably between the arguing pop stars.