Huma Abedin's Devotion to Anthony Weiner a Familiar Subplot

July 24, 2013— -- The notoriously private Huma Abedin, 36, is now publicly standing by her man.

By her own admission, the reasons she chose to defend her husband, former Rep. Anthony Weiner, before the world Tuesday are both public and private: love and politics.

"Quite simply, I love my husband, I love my city, and I believe in what he wants to do for the people of New York," she wrote in a Harper's Bazaar essay that will be published next month.

How Can His Wife Forgive Weiner?

The saga for her has been two years in the making. And unbeknownst to many people until a Tuesday news conference, it continued for at least a year after Weiner resigned in disgrace from Congress for exposing himself to women on Twitter.

Now a leading candidate for mayor of New York City, Weiner, 48, is back in the public eye, and Abedin is campaigning by his side.

And her friends, according to sources close to Abedin, are as surprised as the rest of the public that she chose to publicly defend Weiner after gossip website The Dirty revealed another woman who claims that she had a longstanding sexual relationship with him online.

Of the people inside Abedin's circle of friends, one described being "shocked" and "telling her this is no longer a good idea." Another told ABC News that two years ago, "she was the victim. Now with this yesterday, she's a partner. What is she doing?"

Timeline of Weiner's Online Sex Scandal

Weiner acknowledged Tuesday at the news conference that he had sent sex messages and photos to a woman after he resigned from Congress in 2011 for similar reasons, but he said the behavior is now behind him.

His resignation touched off a period of hard choices and lots of therapy, Weiner and Abedin said.

Clutching the remarks she had prepared to deliver Tuesday, Abedin said the birth to their son Jordan, who's now 20 months old, played a role.

"It was not an easy choice in any way," Abedin said before dozens of reporters in New York City Tuesday. "But I made the decision that it was worth staying in this marriage. That was a decision I made for me, for our son and for our family."

And she's not alone.

American University marriage psychologist Barry McCarthy, who specializes in sexual disorders, says most marriages survive the triumvirate of deviant sexual behavior: eroticism, secrecy and shame.

"The majority of couples and majority of marriages do survive these issues," McCarthy told ABC News. "But there's got to be on the woman's part an understanding that she's not just being a traditional woman, but she is his ally in confronting and halting this behavior."

Abedin's words were like something straight out of a shrink's office, McCarthy said.

"When she says this is between my husband and I, it sounds like a line that would come from a therapist, and it's probably a good line," McCarthy said. "It should not be judged in the court of public opinion."

That line, at least, is a familiar one for women caught on the wrong side of their husband's infidelity.

Abedin's longtime friend and boss former Secretary of State Hillary Clinton notoriously stood by former President Bill Clinton through a protracted and embarrassing impeachment proceeding after he admitted to having sexual relations with White House intern Monica Lewinsky.