I was surprised, and deeply hurt. Despite my shame, I cried openly in the cafe. You see, I was actually angry at him for being sick in the first place, for creating so much disruption in our lives and now this – what felt like a rejection of my love and my strength in holding everything together while he went through treatment. In the following days, I moved like a sleepwalker. The conversation kept replaying in my mind and it would surprise me at odd moments – putting the washing on the line, riding the train into work. I'd find myself feeling ashamed, weeping and cursing my husband for proposing this absurd path. I thought about leaving him. I wondered how I could explain it to the children. Despairing, I confronted him again and said: "Whoever she is, go and f--- her and come back to talk to me afterwards." He denied there was another woman. I suggested a trial separation. He said he didn't want that. Instead, he waited and was loving. He hugged me whenever he saw me. He asked how I was feeling. He did more housework and offered to cook dinner more often. I asked him about the emotional risks of this proposal. What if one of us falls in love with someone else? It will be OK, he said, because we'll still love each other. We'll keep each other safe. I want the connection with others, he argued. It's not just about the sex. I want the feelings, he said. Feelings? I was terrified of feeling. In becoming strong to deal with his cancer, I had locked my feelings away to keep my job, the family and household operational. He wanted to unleash feelings on the world? I had visions of a tsunami of tears sweeping through my life and creating devastation in its wake.

Weeks passed. I began to wonder. I was still angry at him but I began to remember my freedom before we settled down. It was a pretty audacious idea. What if? What might this open relationship look like? There comes a time when you look back at the life before kids – before serious life – and you mourn the loss of the young woman you were. Once upon a time, I danced on tables and wore daring clothes. I took risks and kissed a lot of boys. Could I get in touch with that wild woman I once was? So I read Dan Savage. I looked in the mirror at my body that had produced and nourished three kids and wondered if it could inspire desire in others. Despite being monogamous for 17 years, I considered what sex might feel like with someone else. I went to see a psychologist. I told her I was terrified of grief, of loss and being vulnerable. She gently suggested that there could be great strength in vulnerability too. I have never stopped loving my husband. Like most couples, many tiny conflicts of domesticity come between us and perpetual intimate bliss. But we'd been through so much together, I wasn't ready to give up. I was ready to try something new. I wanted to feel again, even though it terrified me. I was willing to allow myself to feel vulnerable again. After reading everything I could find, I found a sex advice column in a newspaper about a couple opening their relationship and the therapist recommended a workshop-sex play party called Curiosity. I didn't realise it then, but I had discovered what would ultimately be our salvation. Three months after our first difficult conversation, we attended our first session which gave us a safe place to explore, and it introduced us to an extraordinary group of people.

The key theme was the concept of communication, consent and feedback. It's such a simple formula and yet has such a powerful implication on relationships. For the first time, I began to wonder if I could ask for what I wanted, and be open enough to receive it. I felt empowered. And curious about where this might lead. We didn't suddenly jump into the deep end at this party. We watched, talked to people and explored the connection with each other first. We went back the next month and then the month after that. We made friends with other people. We began with some flirtations and a couple of months in, we eventually began seeing other people and building connections with them. The first sex I had with someone new was both wonderful and awkward. His arousal and response to me was flattering. When he called out my name, I felt like a different person, as though the new voice speaking it had changed me. And then I had to deal with condoms again! He didn't know what I liked, I had to tell him. These were discussions I hadn't had with my husband for years. I had to re-learn how to communicate what I wanted. Dating others was intoxicating. For a little while, there were so many opportunities, I found my ego and vanity appeased. We set up profiles on OK Cupid and linked them. We found a polyamorous meetups group and attended regular gatherings. We met people like us who were new at open relationships, and some who had been "poly" for years. I was surprised that I got more attention than my husband. Married, poly women in their forties are still desirable, it would seem. At one point, I had to turn the message notifications off on my phone because it would ping throughout the evening, making my husband sigh and roll his eyes.

We made agreements with each other about dating and family commitments and what was acceptable in terms of nights out and who cooked dinner and took the kids to basketball training. Jealousy rarely appeared. I don't know why. It seems like it ought to have. But I was so pleased that I was desired by interesting and lovely people, that I felt that my husband's pleasure seemed fair and balanced against my own. Also, I genuinely liked the women he dated. My husband and I still made love. We talked often about why we liked certain people, and what we needed from each other. Occasionally, we brought new tricks and skills into our shared bed together that we learnt from others. So today, nine months in, after a lot of dating, things have calmed a little, the new dates have slowed, and we have made sincere connections with other people. Some lovers we have shared together in threesomes and foursomes. Some lovers have become good friends and we've introduced them to our kids. Both my husband and I have "favourites". Our lovers sometimes stay the night. They have dinner with us, and bring cake and wine. My husband's lover brought me flowers when I had a bad day. My lover brought games to teach to the kids. Having a conversation with our kids about our new open relationship was our last taboo. My husband wanted to get it out of the way so he could openly show affection to his lovers but I was worried at how they would cope. In the end, one of our kids noticed I wasn't in our bed when she woke in the night – and simply asked a question the next morning. She hadn't witnessed anything but I felt it was appropriate to explain a few things that we were doing differently from other people. I explained we loved each other the most, but that we loved other people too. She looked a little doubtful but then told me she didn't mind so long as we still loved each other and loved her and the rest of the family. I realise this is only the beginning of many conversations with my kids, and that there will be more, some with higher levels of difficulty. Oddly, this doesn't scare me nearly as much as that first difficult conversation that my husband and I had nearly a year ago.

I reflect on how our lives have changed in the past year. I still love my husband, more than ever. The intensity is made stronger by the delirious energy of new loves. Remember the heady rush of a new relationship – yearning to see a lover's face, feel their touch, and hear their voice? Breathing in my lover's scent after time apart, I find my desire sharpened. It's familiar and different at the same time. It is also precarious and scary. I am in love with him but this love doesn't have the security of the love I have with my husband. There are no binding promises or years of commitment but there is fun and startling honesty. I've found my own vulnerability and it still terrifies me. It is also exhilarating. After my lover has left and I crawl into bed with my husband, he sleepily enfolds me into a spooning hug and I dream I have two loving men in my bed. My husband keeps me safe. I feel loved. The conversations continue. * Name has been changed