Nick, 34, shares four-year-old twins Moroccan and Monroe with Mariah, 45, and he reportedly wants Australian billionaire James kept away from them.
A source told Life & Style magazine: “Nick doesn’t care if you’re a billionaire or a busboy, he doesn’t want his kids around a man he hasn’t met yet.”
Last year 47-year-old James hit the headline for his brief relationship with model Miranda Kerr and for ‘brawling’ on the street with friend David Gyngell.
A source at the time told the Daily Telegraph: “They were beating the hell out of each other – fists were flying.”
Apparently America’s Got Talent presenter Nick doesn’t want that kind of influence around his young children.
The insider added: “He would never bring Monroe and Moroccan around one of his new girlfriends, and Mariah knows that.
“Mariah doesn’t play by the rules. It’s an understatement to say Nick is p*ssed off.”
But it seems like Nick could be fighting a losing battle with his ex-wife, who is allegedly already discussing marriage with James.
Nick confirmed their separation in August last year, after six years of marriage, and later said: “I just wish her nothing but the best. We are in contact constantly.”