I know this is an older thread and you may not be reading it anymore, however, I just had my wife who separated from me sleep with another man. I can tell you that I couldn't stop crying for about a day and a half, another half day of off and on crying. She came to me and said that she was sorry she hurt me, but that was how it is. I made the effort to tell her that I forgave her for her actions, she's my wife (even though she doesn't think so) and sex is just physical. There are so many more levels that she makes me feel good on that I can get past the hurt she caused me on that one level. It sucks, it DOES hurt, but if you make a concentrated effort to tell yourself that there are so many other ways that your husband makes you feel good, then you might find yourself not thinking about it as much and the hurt might ebb. I know that it has for me.