Robert De Niro routinely subjected his longtime employee to creepy and abusive behavior, including leaving her voicemails threatening “you’re f—ing history” and calling her a “bitch” and a “brat,” an explosive new lawsuit charges.

Graham Chase Robinson says for years she was the victim of “gratuitous unwanted physical contact” from the Oscar winner, who also hurled “sexually-charged comments to her” when she worked at his production company, Canal Productions Inc.

Robinson’s allegations against the “Taxi Driver” star are levied in a $12 million lawsuit filed Thursday in Manhattan federal court for gender discrimination and wage violations.

She said she began working for Canal Productions in 2008 as an executive assistant and “forced to resign” in April after rising to the position of vice president of production and finance.

“Robert De Niro is someone who has clung to old mores. He does not accept the idea that men should treat women as equals,” the suit says. “He does not care that gender discrimination in the workplace violates the law. Ms. Robinson is a casualty of this attitude.”

She claims De Niro treated her as his “office wife” and made her do “stereotypically female duties, like housework” while underpaying her and denying her overtime.

The actor, whose latest work includes a role in “The Joker,” also allegedly “urinated during telephone calls” with Robinson, 37, and would greet her wearing only his “pajamas or a bathrobe,” the suit says.

“Among other things, De Niro would direct Ms. Robinson to scratch his back, button his ties and prod him awake when he was in bed,” the complaint adds. “De Niro also stood idly by while his friend slapped Ms. Robinson on her buttocks.”

Robinson said she had to endure De Niro’s jokes about his Viagra prescription and that he directed her to “imagine him on the toilet.” De Niro suggested that Ms. Robinson could get pregnant using sperm from her (married) male co-worker,” the suit adds.

The suit also contains a link to a recording of a scathing voicemail De Niro allegedly left Robinson when she didn’t pick up his call.

“You f—ing don’t answer my calls? How dare you! You’re about to be fired. You’re f–king history,” he seethes.

De Niro and his production company sued Robinson for $6 million in August, accusing her of embezzlement and binge-watching “Friends” on the clock before abruptly quitting. But Robinson claims that suit was brought in retaliation — after she had threatened to sue the actor first.

“De Niro was enraged at the prospect of Ms. Robinson bringing a lawsuit challenging his behavior,” Robinson’s complaint says. “So, he retaliated and struck first.”

Robinson claims she long contemplated quitting but that De Niro would lord his influence as one of Hollywood’s top actors over her, telling her he’d giver her “bad recommendation” if she left, according to court papers.

Now, she’s unemployed.

“What De Niro did to me was wrong,” Robinson said in an email. “The bullying, the inappropriate comments and the demeaning treatment grew so bad that the workplace became intolerable.”

A rep for Canal Productions did not immediately return messages.

A lawyer for De Niro didn’t immediately comment.

De Niro’s bad behavior has been on display before. He snapped at the press calling them “scumbags” earlier this year amid his divorce battle with estranged wife Grace Hightower and blew his lid on his driver after another court hearing.