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Mariah Carey may be poppin' bubbles since Nick Cannon agreed to sign their divorce papers, but she's not sure why he griped about access to their kids in his new song.

That's the latest from TMZ, which reports Mimi doesn't understand some aspects of what Nick has to say in "Divorce Papers," the track he released on SoundCloud and social media last week.

In the tune, he raps, "And now I can't see my kids 'cause the government sucks," and "It's f------ up that the time you spend with your own kids is called visitation."

But sources tell TMZ Mariah's never tried to keep him from seeing their twins, Monroe and Moroccan, who have spent time with their dad regularly since he and Mariah split.

"Divorce Papers" also addresses the fact that Nick hasn't signed off on legally ending his marriage yet, despite having filed for divorce in back in 2014.

"It's been two years and I'm the one that's been waiting," he says in the song.

The line, "Man, f--- it. Let's sign the papers," suggests he's ready to go through with it finally.

Mariah, who's currently engaged to billionaire James Packer, had been married to Nick for six years when they moved to end things.

As for their decision to continue co-parenting their kids, Nick told Ellen DeGeneres at the end of last year that love is the bottom line in their family.

"It's all about unconditional love," he explained at the time. "And knowing because they were so young, this is what they know: They know mommy and daddy still love each other, but more importantly they love us."