Cassini widow locked up

THE widow of Jackie O’s favorite designer, Oleg Cassini, is stewing in Nassau County jail after 10 years of ignoring court orders to share the couturier’s fortune with his children and grandkids.

According to multiple sources, Marianne Nestor

Cassini — who lives in a $15 million townhouse off Gramercy Park — was recently held in contempt of court by a Nassau Supreme Court judge for failing to comply with court orders issued in the tortured, decade-long battle over Oleg’s estate.

According to a legal insider, Marianne was on her way to an “‘Opera in Ver- sailles’ concert at the Metropolitan Museum of Art” on May 3 when she was arrested for contempt by a sheriff from Nassau County, where she also inherited a mansion in Oyster Bay.

“She’s been ordered to do about 50 things” that she hasn’t done, according to the insider. “She’s a stubborn lady.”

After Oleg died in 2006, Christina and Daria, his daughters by Hollywood legend Gene Tierney, were set to inherit half his estate. But both of them died without getting a penny. Now Christina’s son Al

exandre Belmont is suing to force the sale of the Gra- mercy Park townhouse to produce some funds for him and his three siblings, alleging that over a decade of litigation “has exposed Marianne’s malfeasance, misconduct and self-serving abuses.” According to Belmont’s court papers, in 2016, the Nassau County Surrogate’s Court surcharged Cassini to the tune of $50 million for her misconduct as executor of her husband’s estate.