Molly Roden Winter wasn’t planning an extramarital affair. Certainly not a string of sexual encounters with multiple partners, each liaison now intricately catalogued in the public domain. When she stormed out of her Brooklyn home one evening in 2008 – kids crashed out upstairs, husband barely through the front door – it was space, not sex, she desperately craved. “The night this all started,” she tells me, “my husband, Stew, had worked late. And I was pissed off. He’d promised to be home early.” Once again, he’d returned early enough for her to still be awake (for dinner, TV and sex, maybe), but too late to help put the children to bed.

She was 35 then, a middle-school English teacher with two young sons, aged six and three. “I’d taken some time out of work to raise the kids and soon felt lost. I forgot who I was outside motherhood. I felt so devoted to my children. I loved being a parent. I was also angry that my husband got to continue having this whole other life while I did not.” Her husband, a successful writer of music for television, had become the family’s breadwinner; her teacher’s income would hardly have covered the cost of childcare. “It would have made no sense for him to stay home and one of us needed to. But something was bubbling up.” She’d started to suffer migraines, occasionally hives – “a physical expression of my bottled up angst. That night, I’d had enough.” She had no predetermined destination. “I was so out of sorts I didn’t even take my phone or wallet. The second he walked in, I went out.”

Today, Roden Winter, now 52, is calling from her younger son’s empty bedroom. We’re speaking during term time – he’s at college now. It’s the quietest corner of the family home in New York’s bougie Park Slope neighbourhood, and she – much like the airy townhouse the couple still inhabits – presents a quintessentially Brooklynite aesthetic: black sweater, thick-rimmed glasses. We’re discussing her autobiographical debut, More: A Memoir of Open Marriage. Already a major hit stateside, she’s now writing the sequel, and a TV adaptation is in the works. The New York Times labelled the book “breathtakingly candid”, but even this doesn’t quite do justice to how much of herself Roden Winter pours on to the page. As one Daily Mail headline put it: “The misery of an open marriage: X-rated polyamory memoir reveals millionaire Park Slope wife’s agony as husband frolics with lovers, while she endures bad sex in pay-hourly motel and man who ‘forgets’ to use a condom.” Roden Winter would dispute some of the adjectives here, but a dull, preachy guide to the merits of ethical non-monogamy this book is not.

Back to that night. She ran into a friend round the corner – an old teaching colleague a few years her junior. “She was heading to a bar,” Roden Winter says, “and I tagged along. It was there I met this guy, I call him Matt. I was shocked to feel what I felt when I saw him.” Lust, for sure – that longing and throbbing. “I felt a different person. Not just mum, but someone with freedom. I’d not felt that way for such a long time.”

Roden Winter never wanted out of her marriage. But she’d met Stew in her early 20s and he was older. “I’d had my first kid by 29. Soon after we met, he’d said to me: you’ll want to sleep with someone else at some point. He’d had far more sexual partners than me before we got together.” Him dozens, her four. “I wasn’t a virgin, but I was virginal. He’d planted the idea before we got engaged: extramarital relations weren’t a deal-breaker. But lying was. Twice in the first years of our marriage we’d been to sex clubs together. We’d had a threesome with one of his exes. After that, certainly once we’d had kids, I thought experimentation was done, that I didn’t like it. Then, nine years into our marriage, I met Matt.”

In More, Roden Winter recounts all that followed. How, after discussions with Stew, she started sleeping with other men and how her husband found it a turn on. Soon, Stew was having affairs of his own. There were strict rules at first, almost all at Roden Winter’s behest. Initially, the couple opted for a “don’t ask, don’t tell” policy. “That fell apart because my husband is a terrible liar – I was getting angry at him for not lying to me better.” So they made some adjustments. “Then we had a lot of other rules, chief among them: don’t fall in love. I was not setting out to be polyamorous, just to have sexual adventures. The setup was designed to prevent love from happening: no sleepovers, no seeing the same person twice in one week, no dating colleagues or exes.” One by one, however, restrictions were lifted. Often, Roden Winter breached them first. But the promise not to fall in love endured.

For a while, this worked. “I was having some really shitty sexual experiences,” she accepts, “but I figured out what my physical body enjoyed. The pleasure in being transgressive. Having sex in a bar bathroom? I was getting in touch with parts of myself I’d kept at bay.” In time, she began to hanker after emotional connections with potential partners. “And I started to find them. The book ends with me falling in love with somebody else. Stew did, too.”

For many, she understands, this sounds counterintuitive: in such circumstances, standard procedure might be to break up and move on. “But hear me out,” she says. “Other types of love can be expansive.” She points to friendship: loving one friend doesn’t negate your capacity to love another. “That’s how my kids at middle school thought: be my friend exclusively or it’s over. I coached them all to get over it, obviously. With romantic relationships, however, we set these arbitrary limitations.” Look too, she continues, at parenthood. “I was terrified I wouldn’t love my second child as much as my first. Or that I’d stop loving my first when the second came along. Miraculously, my love grew to encompass both. It’s expansive. But in romantic relationships, we’re trained to think that’s not possible. I’m proof it is.”

More documents Roden Winter’s life from 2008 to 2018. “I’ve done a lot of living since then,” she says, “a lot of thinking and experiencing. How we do polyamory today is hugely different to what’s at the heart of the book.” Her marriage has evolved, as has the wider conversation about ethical non-monogamy. At present, the couple are properly poly. “My husband and I both love multiple people,” she says, “and it makes us love each other more, not less.” She has two additional partners: one relationship has been ongoing for three years, the other for two. Her husband is similar. She worked in education until 2022, when she landed her book deal. The interval has made, on the most part, criticism of the book – and, therefore, her own life choices – easier to endure.

“One response,” she says, “has been to tell me how my husband manipulated me into having an open marriage. That I’m a victim of the patriarchy with no agency.” Certainly, he encouraged the idea – Roden Winter being with other men was a turn on for him. “At first, the only way I could give myself permission was by telling myself that Stew wanted me to have sex with someone else. I was still trying to please him.” But therapy reshaped her rationalisation. “Women of my generation were taught to be pleasers. That being a good mother is to take burnt toast and scraps. In time, I realised I was craving something of my own, that didn’t belong to the marriage.”

Needless to say, there have been snipes and revulsion aplenty from conservatives. “Their view is that I’m a pervert and, with kids involved, what we’re doing is immoral. Meanwhile, they’re 19 and 22 and completely flourishing. It’s why I felt in a good position to write the book.”

The moral-outrage brigade aside, Roden Winter feels the book has proved both popular and divisive not because of its content, but who its author is, and what she represents. For generations, queer people – and gay men in particular – have operated outside the marriage, children, monogamy trifecta. Authors such as sex advice columnist Dan Savage have discussed open relationships for decades. Heterosexuals are at it, too: suburban swingers, millions on affair-seeking apps like Ashley Madison, the French. (Her publishers have struggled to sell rights to the manuscript in France, she thinks because they’re so laissez-faire.) Gen Z seem more open to the idea than their parents. Non-monogamy has long-existed across continents and cultures. “The idea it’s an American heterosexual woman, with children, talking so openly? A heteronormative couple breaking the rules and being honest about it?” This, Roden Winter believes, is what’s causing a stir. “It shows that people like me could be anywhere. I have a husband, house and kids. I dress, act and live like a Park Slope mom. It throws people off kilter to imagine they, too, could live like me. That I have children, who aren’t fucked up and I’m not being manipulated or miserable.”

Much of the vitriol, she can’t help but think, stems from readers feeling personally affronted. “But this book is not a manifesto telling anyone to do what I’ve done. Mostly, we don’t see memoir as an author ordering their reader to follow suit.” She argues that reading Cherry Strayed’s memoir Wild, about hiking the Pacific Crest Trail, didn’t make Roden Winter feel immediately compelled to grab her hiking boots and march the 2,650-mile route. “Yet people read something intimate I’ve written and fear it’ll spread like wildfire, and that it’s a direct comment on their own life choices. In fact, it’s not even necessarily about opening your relationship, but giving yourself the freedom to be a whole person with desires that motherhood and marriage might not always fulfil.”

Unsurprisingly, there have been awkward conversations. The book opens with Roden Winter’s oldest son discovering his parents’ open marriage. His father’s OkCupid profile, to be precise. Stepping off an aeroplane years ago, she was greeted to a stream of texts from her then barely teenage child: “Mom, where are you? I need to talk to you! Call me.” And then another: “Mom, are you and Dad in an open marriage?” When he rang, she opted for honesty. “That is how he found a lot out,” she explains. “But just a few weeks ago, he admitted that at 12 years old, a full year before that call, he’d snuck into my closet and read my diaries. We spent so much time agonising over what to tell our kids, but they figure things out on their own.” Full transparency, she’s keen to add, wasn’t only a question of practical pragmatism. “The healthier thing is to have honest conversations and model what it is to be a rounded human-being to your children: a person with, among other things, sexuality and desire.” She distinctly remembers the first time her eldest son learned the basics of how babies are made.

“He was like: ‘Wait a minute, you and Dad did that?’”

“Yes,” she replied.

“Twice?” he asked.

“Yeah, darling. Twice.”

Roden Winter felt this was ample information for a six-year-old. But longer term? “Stew and I were already open then. Long before the book, I was determined to ensure my children weren’t raised to see me as two-dimensional. Of course, nobody wants to think about their mother having sex. Trust me, I get it. But the truth is that mothers have sex. The vast majority at least once. Twice, even.” She winks. “And they might still be at it.” Both her sons are heterosexual. “I wanted them to know that whoever they choose to spend their life with will also be a whole person. Including once they’ve had children of their own.”

Still, it was one thing for honesty around the dinner table and a sex-positive approach shared within the family WhatsApp group, and another thing for your mother to publish a bestselling memoir recounting her most intimate experiences and a decade’s worth of sexual escapades. Her eldest read the book, skipping some of the raunchier sections. “My younger son, meanwhile, does not want to go anywhere near it. Also totally legit.”

A few years before Roden Winter opened up her own marriage, she discovered her parents had a somewhat similar arrangement in suburban Chicago, starting decades previously. “They kept it a secret from us. I didn’t know until I was an adult.” At first, mother-daughter conversations on the topic felt uncomfortable. “As a girl in the 1980s and 90s, sex was generally presented as something to fear: the way you got diseases, pregnant or raped. I did not have any conversations with my mother about the ways in which sex was joyful or connective, a pathway to confidence or self-knowledge.” In adulthood, that dialogue slowly opened up. “I’m not sure I’d have continued with my open marriage without her. She was on the other side of it by then: diagnosed with Parkinson’s, their marriage was no longer actively open. But both my parents retained friendships with former lovers. I see what it means to both of them. She had no regrets.”

And there have been plenty of positive responses to the book: young parents, mothers in particular, in newly opened marriages grateful for seeing their experiences and emotions acknowledged. “And also women who are not mothers, but who are thinking about having kids, or mothers in monogamous marriages. Many women seem grateful that I’m articulating the inner-conflict I’m battling throughout the book: how to be a mother and a whole person at the same time. Where I live, people consider themselves super liberal. You’ll see in shop windows matching mother and daughter sized shirts emblazoned with ‘The future is female’. But the rules for how you’re supposed to behave as a mother are suffocating, I feel. We put mothers into these straitjacketed roles and shame them for not fitting. These rules weren’t made up in my neighbourhood or even in America. It’s almost universal. That’s why this book resonates.”

Frankly, it all just sounds… exhausting? Not the sex, specifically. But managing multiple long-term romantic relationships. “Most worthwhile things are,” she replies. “We don’t say: medical school sounds so hard, just quit. I’d rather be exhausted in my relationship than in a horribly stressful job. It’s about choices.” And, I point out, privilege. She also takes issue with most people’s assumptions at how cumbersome lover-juggling is. “Mostly, straight men believe it will be emotionally exhausting,” she reckons, “and straight women ask: isn’t it sexually exhausting? For my husband, having multiple women in his life has really made him more emotionally aware and happier. Women, meanwhile, presume they’ll have to give twice as many blowjobs: more sexual effort spent doing things they’d rather not. Actually, it’s the opposite.” At least, in her experience. “Anything my husband wants that I’m not into, he can get elsewhere. Our sex life is the best it has ever been. There’s so much less pressure on it.”

Roden Winter’s experience isn’t all easy-breezy, free-love and sexual liberation. She confronts the jealousy and insecurities that continue to come with the turf. “Before this,” she says, “I was seeing either glossy stories about non-monogamy that ignored the warts and problems, or depictions that always ended in divorce. Nobody was writing about how hard it was and how rewarding when it came together.” Her next book will explore the dynamics between her and her husband’s other partners.

Only one rule remains in place today. “If one of us has feelings about something the other is doing,” she says, “we have to work through it together. You can’t say ‘Don’t be jealous’ or ‘It’s ridiculous that you feel insecure’. You have to help the other person feel better. We can do whatever we want, as long as the other’s feelings are prioritised. People have called bullshit on what I say a lot. And all I can say is: I’m not telling you to do it. But it’s my experience. Whether you should try it, though? Well, that’s up to you.”

More: A Memoir of Open Marriage by Molly Roden Winter (Ebury Press, £18.99) is out now