NICKI MINAJ, MARIAH CAREY ALREADY AT EACH OTHER’S THROATS

Mariah Carey wasted no time proving what we told you 2 weeks ago -- there's only room for one diva on "American Idol."  Carey and Nicki Minaj went at it during the first "A.I." taping Sunday in NYC. When Nicki started critiquing a contestant, Mariah would interrupt -- not once, but many times. Each time Mariah interrupted, Nicki fought back by loudly talking over Mariah.