I am dealing with a very similar situation. One difference is, I am the wife who started having emotions for a man who I believed also felt them for me. My husband was not happy when I would cry to him about the problems I was having with this other man. Things settled down and the boy and I started chatting again. Fast forward 9 months later: Now it seems to be over for good. This time I've hidden a lot of the crying from my husband. He knows that I am not happy about the breakup. However, he is really busy right now in a masters program and I don't see any point in upsetting him over a guy who decided that he wants a monogamous relationship with another woman over me.
Like you, this started because my husband and I enjoy me being with other men sexually. The breakup has been very painful for me. Hopefully one day I will find a man who is willing to be a boyfriend to me. It's just hard because the age range of men I am interested in right now seem to be ready to settle down and get married and have more children in a monogamous fashion. That is something that I cannot provide for them.