The Hero singer and the Australian billionaire were engaged to marry after a whirlwind romance, but split in September (16) following a fight while on vacation in Greece.

While previously admitting that she finds the breakup "difficult" to discuss, she seems to have moved past the initial hurt and used the split as inspiration for a new single titled I Don't.

Mariah teased the song on Instagram on Sunday (29Jan17), sharing a short graphic of the words "I Do" being crossed out by red lipstick and replaced with the words "I Don't." She also posted a clip of herself in the studio recording the tune, with the diva dressed up in a white leather jacket and diamond necklace.

"'Cause when you love someone, you just don't treat them bad, you messed up all we had," she sings. "Probably think I'm coming back, but I don't, I don't."

On Sunday's episode of Mariah's World, the star's E! docu-series, the mother-of-two discusses her reasoning behind making the new song.

"Ever since the tour wrapped I took some time just to process my feelings and I started writing a song to express what I've been going through," she explained. "And if you're not getting the love that you need from someone that you're supposed to be in a real relationship with, then why remain in that situation?"

Following her tumultuous 2016, which included her breakup from Packer and the finalisation of her divorce from ex-husband Nick Cannon, Mariah has embarked on a relationship with choreographer and backup dancer Bryan Tanaka. Indicating that the romance has taken a serious turn, at the conclusion of the last episode of Mariah's World, the happy pair is seen taking a trip to Maui and sharing an intimate embrace.

"Here's the thing, I think that this is one of the most beautiful moments, that I'll never forget," Bryan is seen telling Mariah. "And I hope that you don't want to forget it."

The full version of I Don't is set to premiere on 3 February (17).