A source close to the couple says they are no longer living together and are expected to announce their breakup publicly in the coming weeks.
Said one source, “De Niro and Grace are breaking up. He’s been at a few things since the very end of the summer without her — and rumor has it they are done.”
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De Niro and Hightower— a former flight attendant for TWA — met in 1987 when she was working at Mr. Chow in London. They married in 1997 after dating for nearly a decade, and have two young kids together.
The actor filed for divorce in 1999 and they reportedly had a custody battle over their son but they managed to work things out and the divorce was called off.
Robert and Grace renewed their wedding vows in 2004.
De Niro was previously married to Diahnne Abbott. They share daughter Drena, 47, and son Raphael. The “Raging Bull” actor also has 23-year-old twin sons Julian and Aaron, with ex-girlfriend Toukie Smith.
While De Niro has kept his private life out of the spotlight, he previously spoke to PEOPLE about raising his kids
“There are great moments and moments of sadness,” he said. “Sometimes you’re the last person they want to deal with. It’s like when you walk your kids to school and they get older and they don’t want to hold your hand or kiss you goodbye.”