*The solution is incredible simple.*
The wife simply needs to lay down the law. Install an internet filter, password it – do not give him the password. If a page he needs to go to doesn’t load – give him access to that page and only that page alone.
Sometimes you need to be clever against the Satan, an internet filter is your solution.
As a side note – tell him to stop looking at every woman he see’s on the street. It takes a lot of effort and time but this is how you help prevent one thing leading to another. As it says in mesilas yesharim, we cannot alone win against the satan. “Brute” strength against him is impossible, we need to be clever, *and* we need to constantly ask Hashem for help in fighting him, doing it together is the only way.