Mariah Carey made it official ... she will NOT be back at the "American Idol" judges' table for a second season -- and just a few hours later her 'AI' nemesis Nicki Minaj also bolted.
Mariah announced her exit amid rumors that 'AI' producers were going to make a clean sweep anyway before next season.
As we previously reported ... 'Idol' is extremely interested in bringing back Jennifer Lopez to judge next season -- and keeping Mariah and J.Lo would clearly be a bad fit ... and a pricey one at that.
Nicki tweeted her sayonara ... thanking 'Idol' for a "life changing experience."
If you've forgotten just how "life changing" -- TMZ broke the story last October when Nicki and Mariah got into a 4-letter-laced battle royal during 'Idol' auditions in Charlotte.
Still no official word on last man standing, Keith Urban's future. Randy Jackson's already said he won't be back.