War of words!

Mariah Carey and her ex-fiance James Packer's settlement negotiations have been anything but civil.

TMZ reports that Mariah accused James of being a "lying opportunist," with threats of lawsuit swirling as the former couple attempt to end their engagement.

The drama started unfolding after Mariah demanded that her ex-fiance pay up to the tune of $50 million, which has been referred to as an "inconvenience fee." The superstar asserted that James upset her life when he made her move from New York, and that the emotional distress that followed their union led to the cancellation of the South American segment of her world tour.

Mariah also believes she is owed money after being instrumental in many of James business deals, with TMZ sources citing that James secured business by bringing her to meetings in order to seal profitable deals.

The Calabasas mansion the couple rented together is another element of the owed money, with Mariah believing James left her with all of the home's expenses - including staff and security -- in the wake of their failed engagement.

"Entertainment Tonight" reported that their Mariah insiders claim James is attempting to ruin the holidays with these failed negotiations. Their sources shared, "[Packer] is causing Mariah severe emotional distress especially at such an important time of her life. He knows she is the queen of the holiday season and she knows he's trying to ruin it for her."

James, an Australian businessman, reportedly doesn't believe he owes her a dime, especially considering the two were not yet married. TMZ's sources claim that James rebutted that the cancelling of her tour was due to poor ticket sales, not emotional distress from their breakup.

A final point of contention for the couple? The $10 million, 35-carat engagement ring James gave the star back in January.

"His lawyers have tried to get the ring back. They're insisting she give it back… She doesn't want to give it back," sources close to Mariah told "Entertainment Tonight."

The ring remains in Mariah's possession, and is still often featured in the star's Instagram posts, like this one from Nov. 17.

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A photo posted by Mariah Carey (@mariahcarey) on