Marey Carey's career is reportedly being managed by her backup-dancer boyfriend Bryan Tanaka.
The 47-year-old star recently parted ways with her fiery manager Stella Bulochnikov and Bryan has stepped into the role, taking control of Mariah's career as well as her day-to-day life on a full-time basis.
An insider explained to the New York Post newspaper's Page Six column: "Bryan is behind the whole split between Mariah and Stella. Bryan believes that he should be the one running Mariah's day-to-day life, and he's been orchestrating Stella's exit for a long time.
"No one enjoys working with Stella. There's no secret that some people are happy she's out of the picture."
Bryan, 34, started dating Mariah following her high-profile split from the Australian billionaire James Packer.
But the source has insisted he "isn't the right person to run her career".
Meanwhile, another person close to the situation has claimed that Bryan's hands-on involvement with his girlfriend's career is simply an accident waiting to happen.
The source said: "This is a full-on Britney-and-Kevin Federline situation. Brian is a backup dancer, and knows nothing about managing an iconic artist."
Mariah is also reportedly paying Bryan as much as $12,000 a week for the job he's currently doing.
The insider added: "Mariah is in love with Bryan and is like a schoolgirl around him. He has totally manipulated the situation to take over her life and push out everyone else, and Mariah just can't see it."
Mariah's spokeswoman Nicole Perna has denied that Bryan is acting as her manager, but declined to explain who has replaced Stella.
At the moment, the music icon is preparing for her much-anticipated All I Want for Christmas Is You tour, which is scheduled to begin in Ontario, Canada, later this month.