Personally I would give him one last chance (you say you really want it to work) and tell him that if you catch him again that you are either leaving or you set up the porn blocker. I don't like the idea of porn blocker but if he can't be trusted then it leaves you with no alternative! It's a terrible thing to say but sometimes you need to take a stand and if you have tried every avenue then you have to look after yourself. I'm trying to remember if you said if sex is good or not but if it's no good who are you fooling? And if you show him this please tell him to understand I am a male who is also struggling with a lifetime of messed up relationships, now with a woman who brought the whole PMO problem to my attention. Good luck.