Theory - married men who involve themselves heavily in blackmail have a subconscious desire to destroy their marriage. They're unhappy, they're trapped, they almost want their wife to find out so they can confront the marital problems.
In truth, she will most definitely find out one day. A man cannot keep wilfully playing with fire and sending money to women on the Internet and not get burned eventually.
Of course he could just speak with her and suggest therapy for said unhappiness, but we're talking about men here, and you're nothing if not incredibly foolish.
maybe hope for some black magic so the woman falls in love with someone else and leaves the loser behind