The issue here is not with the husband looking at certain sites, but the cause of him looking at those sites. Yes, every man has a tayvah, but it is different to act upon it. For all those who suggest a wife going to a Rov, I would be the first to inform all of you that if my wife ever embarrassed me like that, I would ask for a divorce; and I told her this. If there is an issue she wants to discuss, she should come to me first before talking about it to anyone else. I just find it amusing that couples share the same home, but find it difficult sharing their thoughts and feelings.
Second, as mentioned, before, a Rov is not a marriage counselor and cannot help a couple in the time of need. Yes, he can discuss the halachos, avaros, punishments, etc, but not the cause.
The question everyone should be asking is why is he looking at those sites? What is driving him there? Most likely, there is a fundamental issue in their marriage that only a professional, certified marriage counselor can discuss and resolve.
And if looking at those sites cause alarm enough for a divorce, then the couple should get divorced since it seems the wife does not love her husband enough to help him through this time. The divorce is bound to happen sooner a later; either with him looking at sites, not wearing his black hat in the bathroom, or any other action that she deems inappropriate. My suggestion would be for him to divorce her because as they get older he might get sick and she would not know how to handle it either.