They threw the Facebook at 'em.
At least three educators from city public high schools have been fired in the past six months for having inappropriate dealings with students on Facebook -- one of which culminated in a sexual relationship, The Post has learned.
One of the booted employees is former Bronx teacher Chadwin Reynolds, who "friended" about a half-dozen female students and wrote creepy comments like, "This is sexy," under some of their Facebook photos, schools investigators found.
Reynolds, a former Fordham HS for the Arts teacher, allegedly even tried to get one teen to go out with him by getting her phone number and sending her flowers, candy and a teddy bear.
And despite knowing that the schoolgirls could view his Facebook profile, Reynolds posted a tasteless tagline that read, "I'm not a gynecologist, but I'll take a look inside," according to the special commissioner of investigation for the New York City school district.
Reynolds, 37, protested to The Post that his case "was thrown out. It's not true. The Board of Ed found that the claims were not valid," even though the Department of Education confirmed that he had been cut loose because of the social-networking scandal.
Another ex-DOE employee -- Laurie Hirsch, 30, a former paraprofessional at Bryant HS in Long Island City, Queens -- was canned in May for her steamy Facebook shenanigans involving a student.
She had posted a photo of her kissing an 18-year-old male former student on the lips, which sparked an investigation.
The student subsequently told probers at the Office of the Special Commissioner of Investigation that he had had sex with Hirsch about 10 times in her apartment last year, and records revealed 2,700 phone contacts between the pair over a six-month period.
Hirsch, while not minimizing the extent of her mistakes, said neither she nor the student had been attending school any longer when their dalliance began.
"I was suspended indefinitely" for using a cellphone too frequently during school time, she told The Post. "And it didn't seem in any way, shape or form that I was getting my job back" when the relationship with the boy took off.
In Manhattan, substitute teacher Stephen D'Andrilli also "friended" several female students at Essex Street Academy on Facebook and sent inappropriate messages, according to schools investigators.
He allegedly sent one girl a message telling her she was pretty and told her he had tried to visit her during one of her Saturday classes.
To another young girl, he wrote that her "boyfriend [did not] deserve a beautiful girl like you," schools probers found.
D'Andrilli, who did not return a message seeking comment, was barred last month from subbing ever again.
As part of a wider probe into inappropriate teacher conduct, a fourth employee -- a male teacher at La Guardia HS -- was found to be giving extra credit to students who "friended" him. He was not disciplined.
Despite the flurry of troubling incidents, DOE officials said they don't currently have a policy that addresses teacher-student communication on Facebook.
Still, "we continually look at ways that our policies may need to evolve to keep pace with technology," said a DOE spokeswoman.
School districts in states such as Wisconsin, New Hampshire and Ohio have ordered or urged teachers not to "friend" students on social-networking sites.
Dozens of other districts also have strengthened guidelines governing school employees' use of social-networking sites -- something Internet-safety experts recommend.
"It may be advisable to put it into policy, just because you have too many teachers who aren't going to think this out," said Nancy Willard, director of the Center for Safe and Responsible Internet Use.
"I think it's safer for teachers and students to be interacting on the educational plane -- not a friendship plane," she added. "Socializing on Facebook can cross over into areas that are potentially dangerous."