Four years ago my wife and I split up. It was over money. She had inherited some and we (I) invested it is a business deal and it went bad. She moved out. We have kids. We had always had a very good sex life. She was very adventurous in bed but would not consent to swapping or sharing even though I tried and tried. Anyway after about 3 months of splitting she started seeing another guy. She moved in with him after a while. I knew this would happen as she would need sex. When she was with me she always was up for it. About one year on he got a very good job on fantastic money but in another city. He moved but she stayed for our kids who where in school. It was a friendly split with him caused by his job and career move. About the same time the business turned around as I hoped it would and the investment paid off. I saw this as an opportunity to get her back. The short story is that it worked. It was like when we first started going out again. After a few dates we had sex and she came home to live again. Happy again but then she found she was pregnant. She had changed the type of contraception while with him and never realized until too late. She immediately told him as she was still in contact with him. He was over the moon with being a father. He had never considered or wanted it before. It was too late to terminate it and she was against that anyway. I said that I would be happy for her to have it and the baby would be part of our family. I was just so happy to have her back. She flew up to see him to talk though his issues. She came back after 4 days. He was happy to support the child and wanted to be part of its upbringing as well. When she had ultra sounds and scans he came down and went to the procedures with her. It was his child. It was after one of these appointments that she told me that she was still letting him fuck her. She admitted that they had resumed the relationship the first time she went up to discuss the baby. She thought she could keep us both happy as we lived apart. She did not want to hurt either of us. So we all talked and came up with our arrangements. He continued to see her. Once the baby was born she either flies up with the baby to see him and stays about 5 days or he comes down and spends a long weekend here. He now stays at our place and we all get on well. Before you jump to conclusions we are never 3 in a bed. She would not do that before and still won’t. She has sex with both of us singularly. When he is here she will usually sleep most of the night with me but not before having him first. She will clean up but not shower before coming to bed. It is the only concession she will make in letting me have the shared wife situation. He has told me that he enjoys it as well when she goes from me to him. Neither of us are ever allowed to watch her with the other male. When she flies up to stay with him they get to do what they like. I never hear much about what went on. The baby boy is just 3 and fits in with our family. All the in laws including his family know the situation and we all get on well. We are all meeting for Christmas as we did the last year. Importantly I got her back and we are one big happy family.