Nick Cannon has signed and sealed a deal to write a tell-all book about his marriage to Mariah Carey - and she is furious about him betraying her . Mariah rejected Nick 's numerous demands for a $ 30 million divorce settlement so now he 's writing the book — saying he plans get his payday for being married to her one way or another - and there is nothing she can do about it because he already signed the deal last week with major publishing company Simon and Schuster . Simon & Schuster has confirmed to Daily Mail Online that the book is being published by Gallery Books , an imprint of the high-powered publisher . 'Mariah was willing to give Nick $ 10 million but he said 'hell no ' and demanded $ 30 , ' a family friend tells the Daily Mail exclusively . 'Mariah says it is what they agreed to in the prenup before they got married . Scroll down for video . Battle of wills : Even though they have a prenup that would pay Nick $ 10million , Nick wanted more . When Mariah refused he decided to get his payday through a book deal . But Nick insisted he needs and deserves more than what they originally talked about , but Mariah would n't budge . Now Nick is being very vengeful , dating other women in public including Nicole Murphy , Michael Strahan 's ex , the source says . 'Mariah kept telling Nick she was not going to give him a penny more than $ 10 million , ' says the friend . 'He told her he could write a book and get $ 30 million and much more for a movie deal for all of the crap she put him through over the years . 'Mariah told Nick nobody cares what he has to say and told him to take it or leave it because that 's it - not a penny more . ' The friend believes Nick asked for an outrageous amount from Mariah so when she said 'no ' he could use that as an excuse to go to the book publisher . Nick hardly needs Mariah 's money- although she is worth more than ten times his value . The actor and host of America 's Got Talent has an estimated net worth of $ 20 million . Mariah is worth about $ 225 million . The estranged stars have been going back and forth about this since Nick filed for divorce in December . He was finally tired of arguing with her . ''He says she is being unreasonable so he has to do what he has to do . 'Now Mariah is angry , devastated and scared that Nick will reveal her inner most secrets and make her look like a desperate fool . ' Mariah was crazy about Nick and trusted him with everything in her life but , now she feels he has turned out like every other man in her life and she is completely crushed , the friend reveals . Mariah , 45 , and Nick , 34 , have been battling about money and custody of their twins since he filed the divorce papers four months ago and even though there is a prenuptial agreement Nick is willing to air their dirty laundry — for a big fat check . US singer Marih Carey and her husband , US movie maker and actor Nick Cannon , leave the hotel to have a dinner at the Eiffel Tower in 2012 to celebrate their fourth wedding anniversary . Battle for the babies : Who gets custody of twins Monoe and Moroccan Cannon is another issue in the divorce battle . Mariah and Nick were married on her private estate in the Bahamas on April 30 , 2008 and they welcomed their twins Monroe and Moroccan on April 30 , 2011 . However , in August 2014 , Nick confirmed that he and his wife , Mariah had been separated for a few months and he filed for divorce on December 12 , 2014 . 'Nick says he is going to tell the world about Mariah 's drug use , her strange eating habits , psychosis , what she has said about other artists , her sexual proclivities and her parenting skills . It which will really be hurtful , ' the insider continued . 'And Nick is also going to explain why he thinks he should have full custody of the twins . Mariah has admitted she never wanted children and Nick is going to tell the world why she felt that way . 'If Nick was not willing to spill all of their nasty and salacious secrets he would not have gotten a book deal . So obviously , Simon and Schuster feel this is going to be a blockbuster and they signed him up . '
Nick Cannon has demanded $ $ 20 millionM to settle his divorce from Mariah - even though their prenup calls for less . Mariah has refused and now Nick has inked a deal with an imprint of Simon & Schuster , Gallery Books . Nick filed for divorce last December after six years of marriage . Mariah and Nick have been battling about money and custody of their twins ever since . Nick to reveal secrets about drug use , strange eating habits , her put-downs of other artists , her sexual proclivities .