New York- The curtain rose yesterday in a Long Island courtroom on a sensational $12 million lawsuit – featuring sex, politics and allegations of violence.

William Perks, the former harbormaster of the wealthy North Shore community of Huntington is suing ex-Town Councilwoman Susan Scarpati-Reilly [pictured], claiming she sexually harassed and stalked him after he broke off their 18-month affair.

Scarpati-Reilly, who is married with children, says his accusations would be more appropriate in a “trashy novel” than a legal brief.

Perks, a 30-year employee of the town, which is also named in the suit, claims that he and Scarpati-Reilly had a sexual affair in 1997 and 1998.

They were together for more than 18 months, he said.

The two enjoyed romantic sailboat cruises along Huntington Harbor, after-hours romps in his houseboat, and sexual encounters in her Town Hall office, Perks claims.

“When Mr. Perks wanted their relationship to end, she became infuriated,” said Perks’ attorney, Edward Yule, in his opening statement.

“She did things in her capacity with the town to harm Mr. Perks.”

Perks, 53, charges that at one point, Scarpati-Reilly told him he’d have to get down on his knees and beg for his job – unless he agreed to start sleeping with her again.

And adding insult to injury, the councilwoman moved his office from the scenic waterfront to a dingy trailer overlooking a garbage dump, he said.

Even worse, he claimed, she forced him to work on the “pump-out” boat, which cleaned the toilets of boats docked at the town slips.

Scarpati-Reilly, also 53, denies it all, maintaining the pair never had sex.

They were just friends who worked together, she insists.

In his opening statement, her lawyer, Jason Abelove, described her as a conscientious civil servant, obsessed with doing good work for her constituents.

She claims that their friendship soured because he wasn’t doing his job properly.

“He was a savvy political employee. He knew how to play that game, probably better than my client,” Abelove said. “He got my client in the cross hairs, and he used her and manipulated her for his own personal gain.”

Scarpati-Reilly claims that in February 1999, Perks hit her on the arm as the pair argued over town business. She went to police to have assault charges filed.

The town denied any wrongdoing yesterday, saying both parties are consenting adults.

Yesterday, Scarpati-Reilly settled a defamation portion of the suit. She agreed to pay $3,000 to Perks for calling him a “thief,” sources said.