The lawyer for a Catholic-school teacher who allegedly had sex with students said Wednesday it was the teacher who was victimized and "taken advantage of."

"It's possible her contact with the 16-year-old wasn't consensual," lawyer Donald Kinsella told The Post yesterday, noting the teacher's battle with alcoholism.

In his most expansive comments since Sandra "Beth" Geisel (search) surrendered Monday, Kinsella hinted a 16-year-old boy who authorities said slept with her might have forced sex on her or coerced her. "It's possible that the 16-year-old may have some criminal responsibility in connection with this matter," Kinsella told Albany radio station WROW-AM.

"I'm not saying that there was physical force involved with each of the incidents with the 16-year-old; there are other possibilities concerning coercion that don't amount to force in terms of using a situation as leverage."

He wouldn't comment to The Post on whether she'd been threatened with exposure — but said people will have reason to "determine who the predators are."

He also blamed the boy's father for pursuing the matter with authorities to get even with the Christian Brothers Academy (search) in Colonie for expelling his son.

School officials wrote in a letter obtained by The Post that the father threatened to bring a "s---storm" of trouble for the academy if it did not reinstate the boy, which did not happen. The boy's father called the school charge "total propaganda."

Colonie Police Chief Steven Heider seemed surprised at Kinsella's comments. "We'll let the facts stand as we presented them," he said.

Geisel, 42, has been charged with two counts of statutory rape and two counts of endangering the welfare of a minor.

A spokesman for Albany County District Attorney David Soares (search) confirmed yesterday Geisel could face a third charge for having sex with the 16-year-old a third time. Kinsella did not deny during the WROW interview that the mother of four had sex with the 16-year-old or three 17-year-olds at various times.

In New York the legal age of sexual consent is 17.

"What happened here primarily is her responsibility," Kinsella said, however adding there are factors "where a reasonable person might think that she was taken advantage of."