When Maureen Sherry resigned from Bear Stearns after 10 years, she was given a going-away party, a sizable check — and a nondisclosure agreement.

“The legal department gave me this document to sign,” she says, and the money was a bribe: Don’t ever talk about the things you’ve seen here, or the way you were harassed, dehumanized, humiliated.

Sherry refused to sign and declined the check. “Me taking money,” she says, “wouldn’t help anyone coming up after me.”

Her forthcoming novel, “Opening Belle” (Simon & Schuster), a thinly fictionalized account of her 11 years on Wall Street, is the result.

She also interviewed young female traders working on the Street today, and found not much has changed.

For all of the horror stories she tells — the sexual degradation of female traders, the marginalization of women who were married or had kids — Sherry insists she didn’t have it so bad. A colleague may have guzzled her breast milk, and another may have left unwrapped condoms strewn in her pizza box, but, she says, “a lot of it was pranks. I never got groped.”

And herein lies the conflict so many women on Wall Street still struggle with: The very firms that have made them wealthy and successful have also abused them terribly — and like so many victims, many of these women feel it’s somehow their fault, their problem to fix.

Sherry points to Sallie Krawcheck, who was publicly fired from Bank of America during the mortgage crisis. Now “she runs Ellevate — it’s a membership thing for women. A lot of it’s about strategies, and how to work better with men.”

But why, she’s asked, should the onus be on women to work around men who treat them poorly?

Sherry pauses. “Right?!”

Wall Street, she adds, “is like ‘Downton Abbey.’ No one likes change.”

Sherry opens her book with a Christmas party: Her stand-in, a successful trader named Belle, is nearly punched out by a younger male colleague who’s using her 4-year-old’s Barbie head as a football.

“A trading floor has everything to keep the adrenal glands pumping cortisol,” Sherry writes. “Breaking news, tragedy, money, racism, sexism, and a little less overt sex play than in the past. The blow-up dolls that floated around in the early ’90s have been deflated, and the deliveries of erotic chocolates have ceased.”

The bar has been set incredibly low.

Among the anecdotes in Sherry’s book: Men openly debate hiring women based on their looks. One young woman sees her breasts drawn on top of her résumé. “The Dais of the D- -ks” is where the top male earners and producers sit; from there, they bark at the women through a microphone to come stand before them and suffer through “Game of Thrones”-style humiliations.

‘Women filing complaints feel like it reflects poorly on them — that they are weak, non-team players.’ - Maureen Sherry

A male trader moos at Belle when she’s lactating — something Sherry admits happened to her often, and by more than one trader.

“I ignored the time someone taped torn panties on my screen when I came back from my honeymoon,” Belle says. “I don’t want to hear slut jokes all day long. I don’t want to work in a frat house.”

A former colleague of Sherry’s, who asked not to be named, says it’s even worse than that. “Men getting b- - -jobs in front of staff — that happened all the time,” she says. “Lots of things that were extremely shocking, pretty disgusting.”

She’s still a powerful figure in finance, but is afraid to say more — even off the record.

Sherry herself says female traders often fall prey to an insidious reverse psychology: Are you tough enough to take it? How can you move billions of dollars around if you can’t take a little workplace hazing?

“Women filing complaints feel like it reflects poorly on them — that they are weak, non-team players,” Sherry says. “They don’t want to be labeled as a troublemaker. It’s a team environment, and they’ll ostracize themselves if they do so.”

Most everyone who goes to work on Wall Street is made to sign a U4 — a document stating that any grievances will be settled in-house. It’s meant to fend off sexual-harassment suits and fosters a secretive, hermetically sealed environment: Bad behavior stays behind closed doors.

That’s why the few lawsuits that do make it out sound so cartoonish as to be made up. In our post-post-feminist, politically correct culture, sensitive to race, gender, sexual orientation and all manner of micro-aggression, how could men possibly behave like this?

And yet, in 2010, Karen Lo, an intern at Guerriero Wealth Holdings, sued her boss, Thomas Guerriero, for sexual harassment. Among the texts she claimed he sent her:

“I wanna make you c- - like u never had is that a bad thing I know ul love it.”

“[Your boyfriend’s] lil d- -k please don’t make me touch myself thinking bou you lol at least feel me close.”

“I wanna take you in the stairwell on the low wat u say . . . I know ul love it. Meet me there I wanna touch you already.”

That same year, Dorly Hazan-Amir was one of six women suing her former employer, Citigroup, for sexual discrimination. She claimed male colleagues talked about a betting pool over how much baby weight she would gain, made sexually explicit remarks in front of her, told her she could attend conferences “when you learn how to play golf,” and demoted her when she came back from maternity leave.

In March 2010, three women filed a gender-bias suit against Bank of America, and in September, three women filed a sexual-discrimination suit against Goldman Sachs.

A refiling of that suit in 2015 claimed not just pay gaps and discrimination but that “Goldman condones the sexualization of women and an uncorrected culture of sexual assault and harassment.” One of the plaintiffs claims that she “was sexually assaulted by a married male colleague” after a business dinner, and that when she reported it to higher-ups, she was demoted.

In 2004 and 2007, Morgan Stanley settled two gender-discrimination suits for more than $100 million. The plaintiffs: thousands of women.

“When you first get to the Street,” Sherry says, “it’s a slow realization” that abuse comes with the job. Sherry grew up middle-class in Rockland County and was drawn to finance because “I loved the idea of a career where you move quickly and you eat what you kill.”

Yet she and her female colleagues — among the best and brightest — were sidelined, especially once they became mothers. The attitudes toward women, she says, are beyond regressive.

“When I first returned from maternity leave,” Sherry says, “there was this feeling that, ‘You should be home with your child’ — unless it’s a financial necessity to keep your family off the bread line.”

During interviews, women have been asked whether they are married, whether they have plans to marry and, if so, to promise never to have children. In her book, the few female traders sit together along what’s pejoratively called “Estrogen Row.”

She has a male colleague explain the firm’s thinking:

“You’re all fertile lassies. [We don’t] want some bumper crop of equities markets pushing ever higher while [we’re] caught with sowers and reapers who aren’t available to harvest the goods. If the reason they’re unavailable is because they’ve been having unprotected sex . . . you ladies are a pain in the ass.”

Sherry says it’s this Cro-Magnon attitude that explains why so few females make it to CFO — or anywhere, really, where they can exert real power.

“I hate that the example is: If you have a baby, you have to be back in two weeks,” Sherry says. “And there’s someone in the book like that because there was someone at work like that.”

The irony, Sherry says, is that working mothers often become more productive and efficient because they have to. “I was talking to two other moms on the Street about how we became, as mothers, much more organized,” Sherry says. “But we weren’t taken as seriously.”

‘When I first returned from maternity leave there was this feeling that, “You should be home with your child” — unless it’s a financial necessity to keep your family off the bread line.’ - Maureen Sherry

Then there are the male traders — less productive, less hardworking — who make double what the women do. Often, the excuse is that men can do what women cannot: comfortably entertain male clients on golf courses, at strip clubs and brothels.

“The disparity of gender pay is exactly the same,” Sherry says. “Young female traders are frustrated that they’ve done all the right things, yet are still doubted about their ‘commitment to the job’ ” — code for marriage and babies.

In the book, Sherry’s doppelgänger is paired with a lesser-performing male trader, which means he’ll earn half of everything she brings in. When she complains, her male boss says: “The guy is getting married to a woman who is a shopper. Then he’ll have kids, and if he sees no place to grow his business, he’s gone.”

Women, Sherry adds, can often be their own worst enemy. She recalls interviewing a female trader who said she resented colleagues who took maternity leave.

“She said, ‘I don’t appreciate it when one of my co-workers leaves for four months and gets the same bonus.’ ” Sherry asked how people felt about a male colleague who had a heart attack and needed an equal amount of time off.

“She said, ‘Well, we all felt really sympathetic and supported him.’ ”

For a moment — a super-brief, blink-and-you-miss-it-moment — there was a great discussion point after the 2008 financial collapse: Could the crisis have been averted, or at least mitigated, if there were more women in positions of power on Wall Street?

In 2014, in a column called “Eight Things I Wish for Wall Street,” author Michael Lewis wrote that women should be in charge.

“Men are more prone to financial risk-taking and overconfidence,” he wrote. “Trading is a bit like pornography: Women may like it, but they don’t like it nearly as much as men, and they certainly don’t like it in ways that create difficulties for society. Put them in charge of all financial decision-making and the decisions will be more boring, but more sociable.”

Sherry agrees. She also thinks there’s only one thing that could make Wall Street renounce its deplorable, chauvinistic attitude toward women: money. A 2014 report from the White House Council of Economic Advisers found that more women complete college and grad school than men, and make up a larger percentage of the work force.

That same year, Forbes magazine reported that women in their 20s without children out-earned their male peers. And a 2013 Pew Research Center report said women are now far more likely to be their family’s primary breadwinner.

That’s a lot of women with a lot of money to invest, and chances are high they’d rather not negotiate at a strip club.

“On the other side of these trades in corporate America,” Sherry says, “is 50 percent of the population. We’re just a different country now.”

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