I was sitting at DK Donuts in Boise, Idaho, on a dreary November day, talking by phone to my therapist in London, where my husband was, and where I should have been too, if I hadn’t fallen in love with another man and upended our world.

It was a spectacular betrayal. I had been close with David’s wife for years, as he had been with my husband. We shared long Sunday lunches, holiday meals, had five decades of marriage between us and five children. Although there was always a gentle attraction between David and me, we never spoke of it.

But in the months between my husband leaving to work in London and the end of the school year in Idaho, when I planned to join him with our teenage children, David and I crossed a line. We found ourselves in an old western bar one night after a fund-raiser. A band played, we danced too close and said things we couldn’t take back, even though we tried the next day, and kept trying, until the pull was too great.

From spring to summer, we debated whether to tell our spouses, the harm we would cause by leaving them, the happiness we might miss if we didn’t. Despite my husband’s dalliances, he and I shared a rich intellectual connection, a big life. Our children felt secure. David’s were grown but still in early adulthood. We had compromised in our marriages, denied parts of ourselves, often felt lonely, but who didn’t? Weren’t we happy enough?

We tried so hard just to think. But reason was no match for our frantic, raw desire.

Soon after the children and I moved to London, my husband asked me one morning, straight out, if there was someone else. I had deceived him for four months and couldn’t anymore. David told his wife the same day.

That was the day I first met my therapist.

I walked to his office through neat Edwardian neighborhoods fringed with fall color, trying not to come apart. He opened the door, a tall, elegant man with silvered hair, a firm handshake, kind brown eyes. He offered me an alcove seat surrounded by trees, a place I could breathe.

Trembling, I told him the story, trying to be fair to what my husband must be going through.

“You have an equal share in the failure of your marriage,” he said. “This doesn’t change that.”

It startled me how clear-eyed he was when I had no clarity at all.

Week after week he listened. I told him David and I wanted to be together but couldn’t see how without causing unimaginable pain. The storm we had tried to anticipate was a tempest. Our spouses might never forgive us; we didn’t know if we would forgive ourselves. I didn’t want to go back to my marriage but didn’t know how to leave it.

My husband pleaded, cajoled. He implied my life would shrink to the size of a postage stamp, and then I would know the terrible mistake I had made. When he was sad and reasonable, I felt worse, his hurt almost unbearable.

My therapist said that when he asked me what I thought, I often told him what my husband thought instead. People who knew us had started to weigh in — I was a bad wife and mother, had ruined a good man. He wanted me to trust my own voice, not theirs.

I told him I knew there was dopamine coursing through my brain, but that I had found, with David, a way of loving I recognized as love. Being with him restored me to some essence of who I was as a human being.

“Do you hear how lucid you are when you say that?” he said.

He counseled me through telling my children, terrified as I was. My son had left London for his freshman year in Cairo, where the Arab Spring was at full tilt. I had to tell him over Skype. He would not speak to me for almost a year.

My two daughters were paralyzed, in shock, and grew distant.

If I lost them, I didn’t know if my center would hold.

My therapist told me I needed time — there was so much to discover about myself in this new place. Being true to that self might eventually help them understand.

I went back and forth between London and Boise, trying to come to terms with what I had done. My therapist kept listening, wherever I was. The more I talked, the clearer my thinking became. I finally agreed to leave our London house for good when my husband promised to bring our daughters home after Christmas.

In Boise, even acquaintances took sides, called me names, averted their eyes in the grocery store, crossed the street to avoid me. Old friends dropped me without a word. Everywhere felt like exile.

I told my therapist the tiny table at DK Donuts felt like the postage stamp my husband had predicted. “My best friend says I’m a pimped-up, postmodern Hester Prynne,” I said, “who’d better start embroidering her own Scarlet A.”

I could almost hear him smile.

“Stand up for yourself,” he said. “She’s right. Don’t let yourself be punished for choosing happiness.”

With his gentle but sturdy support, I began to reclaim my voice, my power. Despite the fear and guilt, I sometimes felt a sense of expansive possibility, the exquisite beauty of being human. Frightened as I was, turning back would feel like cowardice — that I wasn’t brave enough to reimagine my own big life.

We agreed it didn’t make sense for him to counsel me anymore, being an ocean apart. I needed to find someone at home.

I flew one last time to London before Christmas in hopes my girls would see me. I took a room in a nearby house, lingered in cafes and waited. Alone, I wandered the holiday bazaar at the Barbican, feeling its brutalist angles, the alienation from my old life.

But I knew I would get through it.

And suddenly my therapist and I were having our last session.

Just before the hour was up, he said, “For the sake of closure, maybe you could tell me what this experience has been for you.”

I wasn’t prepared for the question, but I had so much faith by then. I said when I felt like I was disappearing, he saw me. When I told him what was true for me, he believed it. “I couldn’t have gotten through this without you.”

He gazed out the window and steepled his hands under his chin, gathering himself. Then he looked at me. “I know this is unusual,” he said, “but I’d like to tell you what the experience has been for me.”

I knew he was asking my permission. With no idea what he would say, I nodded.

“I am the child of an affair my mother had with a man she loved and left her husband for,” he said. “She had three children, but she never saw them again. I lived with her grief, and her guilt, all my life. She never forgave herself.”

I felt my chest sink. Nothing could have prepared me.

“I’ve tried so hard to be your advocate. I want you to have the happiness you deserve,” he said with a wistful smile. “But the whole time we’ve been in therapy about this, I’ve been in therapy about you.”

I looked out the window too, trying to take it in.

My story had reawakened the hurt he had carried — the tragedy of his mother, who had chosen her own happiness and suffered for it the rest of her life. But rather than turn away, he had stayed with me. He had used it to grow as a human being, the very thing he had encouraged me to do.

Sharing his story felt like an act of deep compassion and generosity. He knew I could integrate it, as part of my larger experience.

The story of women does not have to be repeated. We can rewrite it — and must.

He believed in my agency, that only I could say what would make me happy, who I wanted to be, and with whom. He was hopeful my children would come to see me as more whole, and more capable of nurturing them, which they have. He accepted my vision of a loving, equal relationship with David, which we still have today, 12 years later. He trusted me with my own life.

Maybe, in our time together, he was talking to his mother too. To all mothers, all wives, all women, across time. But mostly, he was talking to me.

I walked away into wintry London, unsure of the future but not the path. With his help, I had found my way.

Samantha Silva is a writer whose latest novel is “Love and Fury.”

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