I’m 34 years old, a nurse, and married to my husband for eight years. We have two children, and I honestly believed I had a happy family. At the hospital where I worked, I had a colleague who was also my best friend. She was 31, a single mother, and lived just a few streets away from me. Our children played together, we shared meals, and we spent so much time together that our colleagues often joked that we were sisters. I trusted her with everything, including my marriage problems. What I never knew was that whenever I worked night shifts and she was off duty, she would visit my house and sleep with my husband. The most painful part? She would sometimes call the hospital to ask how busy our unit was, trying to find out whether I might finish early or be sent home. One night, another colleague noticed something suspicious and eventually the truth came out.