n 2008, after five years of marriage, my wife and I had allowed work and family obligations to take their toll on our intimate life. Sex had been relegated to non-priority status, and we were having it once a month or less. Then, on New Year’s Eve, my wife got drunk at a party. After she’d passed out at home, I found myself checking her phone, and discovered a string of messages she’d exchanged with a male friend of ours. For three months, they’d been swapping nude pictures and discussing meeting for sex. I confronted my wife the next morning. I confided that I was hurt by the texts, but also aroused, and pleased to discover that she still had a sex drive. She assured me there were no romantic feelings between her and our mutual friend, only the playful, pornographic texts. We talked for eight hours – the future of our marriage was at stake. I decided to give her licence to pursue a physical affair, so long as I knew when and where they were meeting. A year later, this resulted in the three of us enjoying a drunken threesome; and in the 12 years since, he has visited the house once a month or more to repeat the experience. It’s an arrangement that has saved our marriage. We live in a very small midwestern town in the US and have successfully kept our lifestyle a secret – but it seems to have given us a much more satisfying sex life than most couples our age. • Each week, a reader tells us about their sex life. Want to share yours? Email sex@theguardian.com. All submissions are published anonymously, and subject to our terms and conditions.