It sounds to me like he moved you there so he could have an affair. She will always be a danger to your marriage as long as you live so close so I would strongly recommend you move. The affair could start up again in 2 seconds. Just think about how addicted he is to her. He moved his family 1500 miles to be with her so think about that. Living there is very dangerous to you.
He looks at porn too, doesn't he?
Passwords, emails etc none of it matter. I had full access to all known emails and phones etc. I had all his passwords etc to the stuff I knew of. It was all the secret apps and emails that he did a great job of deleting and hiding that I didn't know about that was the issue.
This is where you should focus. He should not have the ability to have any secrets. For example if he carried on his affair on a smart phone, he should get a flip phone. If he carried on his affair on a computer, he should never be on a computer again unless you are there. This is a critical part of affair proofing your marriage. He should construct his life so it is impossible for this to happen again.
Please read this list over and tell me where you stand:
From Surviving an Affair, pg 66-67
The extraordinary precautions do more than end marriage-threatening affairs; they help a couple form the kind of relationship they always wanted.
These recommendations may seem rigid, unnecessarily confining, and even paranoid to those who have not been the victim of infidelity. But people like Sue and Jon, who have suffered unimaginable pain as a result of an affair that spun out of control, can easily see their value. For the inconvenience of following my advice, Sue would have spared herself and Jon the very worst experience of their lives.
Checklist for How Affairs Should End
_____The unfaithful spouse should reveal information about the affair to the betrayed spouse.
_____The unfaithful spouse should make a commitment to the betrayed spouse to never see or talk to the lover OP again.
_____The unfaithful spouse should write a letter to the lover OP ending the relationship and send it with the approval of the betrayed spouse.
_____The unfaithful spouse should take extraordinary precautions to guarantee total separation from the lover OP:
_____Block potential communication with the lover OP (change e-mail address and home and cell phone numbers, and close all social networking accounts; have voice messages and mail monitored by the betrayed spouse).
_____Account for time (betrayed spouse and wayward spouse give each other a twenty-four-hour daily schedule with locations and telephone numbers).
_____Account for money (betrayed spouse and wayward spouse give each other a complete account of all money spent).
_____Spend leisure time together.
_____Change jobs and relocate if necessary.
_____Avoid overnight separation.
_____Allow technical accountability.
_____ Expose affair to family members, clergy, and/or friends.
and made the mistake of reading them......