Just because he cheats doesn't mean he is a sex addict. Perhaps he is feeling there is something "missing" in your relationship that was once there but he doesn't see/feel anymore? If that's the case, you can possibly work through it with relationship counseling. You both need to be willing to talk openly though about what you are feeling and why. Nothing can be done unless you are willing to do that. As far as repeat cheating - he was completely faithful eleven years, that's why I think it's something he feels changed in your relationship. If you can find a way to repair whatever changed and rebuild the trust, I don't think you will have to worry about repeats. One thing I will caution you on though. If you do decide to remain in the relationship and try to make it work - don't be overly suspicious of him everytime he gets online or glances in the direction of another female, and don't accuse him of wanting to cheat or of cheating everytime (or almost everytime) you argue or continously bring up this situation when you argue in the future either. I am not saying any of that to be harsh on you but rather to try to help you save your marriage if that's what you intend. I know it will be very hard to trust him again. Thing with trust though is in order for it to be re-built, you have to care enough to offer it back out again and see where it lands. And if you keep bringing up this, it will keep you stuck here and won't ever let you move on to rebuild that trust - and if you accuse him or suspect him at every turn, he will feel defeated and eventually end up sabotaging things. I hope things work out for you - whatever you decide.