Kim Zolciak BF's Ex Rushes to Court Over His Alleged Spending on 'RHOA' Alum

The estranged wife of Kim Zolciak's current boyfriend, Kyle Mowitz, is making moves to block his spending habits to ensure there's still money to pay her at the end of the divorce -- claiming he's been dropping crazy money on the 'Real Housewives of Atlanta' alum and his lavish lifestyle ... TMZ has learned.

According to court docs, Jillian Green -- who's in the middle of a divorce from Kyle -- claims he spends lavishly on Kim and her family, including covering legal fees in Kim's own divorce from Kroy Biermann.

Jillian wants an injunction to prevent Kyle from spending such substantial sums, and wants some money put in escrow so she can get paid what she's entitled to in the divorce down the road.

In the filing, Jillian says his spending is "out of control" and insists "there is every reason to believe the millions of dollars" he is expecting from his business "will disappear quickly" without court intervention.

She claims Kyle has spent money on an expensive car, trips, wine, and his celebrity girlfriend ... and thinks he will spend more on large purchases or loans to Kim -- who she calls his "potential future wife."

Jillian claims Kyle has been paying large sums on Kim’s rent, as well. She's asking the court to intervene immediately.

As TMZ first reported, Kim was dragged into Kyle and Jillian’s divorce last year after Jillian subpoenaed Kim in an attempt to depose her.