A warning to any and all New York politicians considering an extramarital dalliance, virtual or otherwise. When you eventually hold your de rigueur regret session at a packed Manhattan news conference, Andrea Peyser will be there in the footlights, ensuring that your fall from grace is as graceless as humanly possible.

“Your wife is not here!” Peyser, a columnist for the New York Post, shouted up to Rep. Anthony Weiner (D-N.Y.) during Monday’s megagaggle at the midtown Sheraton. She stood in front of the front row of seated reporters, her shadow and trademark bob projected onto the wooden lectern from which Weiner spoke.

“Are you going to split up?”

Weiner replied that he and his wife intended to “weather” the storm. Peyser was not satisfied. “Where is she? Where is she? Sir, where is she?”

“She is not here,” Weiner said.

“Where is she?” pushed Peyser, who later asked, “You said you were on the phone. Did you have phone sex with these women? Did you ever have some kind of an affair with some of these women?”

Weiner clarified that he was never in the same room with any of the women.

“Did you have phone sex? Did you have phone sex?” asked Peyser, adding, “These were young girls, very young, a 21-year-old, does that bother you? They are young enough to be your children.”

It was no accident that Peyser stood front and center at the Weiner news conference or that she became its virtual co-star. When it comes to humiliating humiliated powerful men and the women who stand by them, Peyser is unparalleled. As former New York governor Eliot Spitzer walked toward the door with his wife, Silda, after basically admitting to paying prostitutes, the last thing he heard was Peyser calling after the couple, “Silda! Are you leaving him?”

Peyser has long been an object of fascination among some media observers in New York, who count her unforgiving, exuberantly spiteful columns as a guilty pleasure. New York Magazine described her as “the local Madame Defarge, shaking her fist as the tumbrels roll by.” The New York Observer called her a “roving Valkyrie reporter-commentator” and Web site the Awl on Tuesday dubbed her the New York Post “harridan.”

There are less flattering names, too.

“I don’t like that word, ‘scold,’ ” said Peyser, who made no excuses for attacking Weiner. “I only go after people who ask for it. He was asking for it. DSK [Dominique Strauss-Kahn] asked for it. Tiger Woods. Go down the list.”

Peyser, who grew up in Queens and now lives in Brooklyn with her husband and daughter, became a columnist during an alleged sex scandal involving New York Mets players in the early 1990s. She said she learned that “during spring training, the boys were very bad.”

The experience also taught her a more consequential lesson. “I discovered I’m not afraid of scandal,” she said, adding that these sorts of stories rivet her to this day. “Human behavior never ceases to amaze me. Human stupidity never ceases to amaze me.”

And wives who support their disgraced husbands never cease to amaze her.

“It’s only expected,” Peyser explained, “that if you are standing by a person who has broken the law or broken marriage vows or strayed in some way that your motives are going to be questioned as well.”

Weiner’s wife, Huma Abedin, a close adviser to Hillary Rodham Clinton, has so far acquitted herself well in Peyser’s eyes because she refused to appear with the congressman in his moment of shame.

In Tuesday’s New York Post, Peyser wrote, “The gorgeous and furious Internet cuckold Huma Abedin refused yesterday to stand by her man. She did not show up to walk the plank of public humiliation, the way doormat Silda did.”

Not everyone appreciates Peyser’s morality. The gossip Web site Gawker has combed her columns for racism, sexism and just about everything else. (She recently blamed “the majority of the citizens of France” for the alleged rape of a hotel cleaning woman by former IMF chairman Strauss-Kahn.) Longtime New York Post watchers recalled one column Peyser wrote that garnered so much angry mail that the tabloid published it under the headline “Peyser. They despise her.”

Peyser said she didn’t remember that particular headline but did recall that one column, in which she argued that the felony trial of a man who had drunkenly stomped his girlfriend’s cat to death was a waste of money, prompted an inordinate amount of hate mail. She called it “the one time that people went nuts.”

Not exactly the one time.

Peyser has been sued, unsuccessfully, by both the Rev. Al Sharpton and the late celebrity lawyer Johnnie Cochran. A puncturer of outsize egos, she had her bubble burst in a 2005 New York Observer story. Headlined “Peyser Permanente,” it chided her for keeping the label “Columnist of the Year” under her name in print for more than a month after the association that bestowed the honor awarded it to someone else.

Peyser’s fearless reporting style (she approached Woods as he hit a tee shot at a tournament), hatred of celebrities (what Lindsay Lohan “desperately needs is a swift kick in the teeth”) and writerly flourishes (“his fetishistic fixation with phone sex”) are, she said, all in a day’s work. If she doesn’t ask the tough questions and write the blistering columns, who will?

“I would like to think that there is a lot of humor in it as well,” she said. “And there is a lot of humanity where it is warranted. I don’t think that I’m a mean person.”