"There is trouble in paradise," the America's Got Talent host told The Insider on Thursday, according toUs Weekly. "We have been living in separate houses for a few months."
Cannon -- who has three-year-old twins with his wife of six years -- reportedly added, "My main focus is my kids," without exposing what problems have brought the high-profile couple to hit rock bottom.
A source told Us that Cannon, 33, and Carey, 44, have been separated since June and it's been "shaky for a while, but it all came to a head recently."
"She is heartbroken," a different source told E! News. "This has been going on for months. It has a lot to do with Nick's career choices. He does not have to work but he's been throwing himself into gigs and projects."
Carey has allegedly "tried and tried" to get Cannon "to stay home more," as he's often on the road for DJ gigs and other appearances.
"But he always uses work as an excuse," the E! News source explained. "When she points out that, financially, he does not need to be working as much as he does, it pisses him off and pushes him farther away. He hates when people assume he's living off her money."
Carey would reportedly like to be in New York City full-time and wishes Cannon would spend more time with their kids.
"If and when they split," the E! News source continued, "she intends to stay in NYC with the kids. She will fight for the kids. She is totally focused on them."
Although Cannon's work ethic appears to be the root of their issues, the E! News source also insisted Cannon may not have been faithful to the pop diva, which has caused Carey to lose trust in her husband.
"Recently, she found out he's been talking to a girl in LA," the source told the website. "He insists she's just a friend, but Mariah has doubts. The distance he puts between them doesn't help. He's always traveling."
TMZ had reported Cannon often disclosed too much personal information to the public about his sex life and relationship, which infuriated Carey, and the divorce is "a done deal."
"They are not getting along," a source close to Carey told E! News. "She wants to end it and it has been in the works for months, which is why her house in the Bahamas and the house in Bel Air are on the market."
Up until now, Cannon had denied speculation that his marriage is crumbling. He told Parade magazine back in May he just ignores the "humorous" rumors and they "couldn't be further off from the truth."
Carey and Cannon wed in April 2008 and welcomed their twins, Monroe and Moroccan, in April 2011. They've had a pattern of renewing their vows every year as a way to celebrate their anniversary.