Things are about to get uglier for 'Real Housewives of New York' star Jules Wainstein -- her estranged husband is planning to file for full custody of their 2 kids ... TMZ has learned.
Sources close to Michael tell us his attorney is prepping docs asking a judge for primary custody ... He also wants an order limiting Jules to supervised visitation of their 2 young children.
This, of course, comes on the heels of Jules calling 911 Wednesday morning after the 2 engaged in a nasty argument. As we reported ... Michael left before cops arrived. No one was arrested.
We're told Michael will claim Jules is just too erratic to have the kids.
Jules won't comment on Michael's allegations.