I...don't like to be negative about things, especially marriages, but this strikes me as a huge red flag.

Do you know if he's made good on any of the ads? Can you think of any excuses he's had to be away around the suggested meet up times, if you know them? I'm not so lenient on whether or not he met these women in the severity of what he's done/doing, but it does make a difference.

I'm curious...are these simply nude pics? It strikes me odd that you two get along so well and yet he's seeking outside sexual gratification. I'm almost wondering if he has some type of fetish or something that he doesn't feel comfortable sharing with you. I don't think that excuses him one iota, but it's worth consideration.

If I were you, I'd confront him. He's going to try to defend himself by asking you why you were snooping through his personal files. Be prepared to answer that (I'd recommend reminding him why you felt the need to, and that it was validated). He owes you an explanation for this. I'd also recommend couples counseling for the both of you to try to work past this, if you're inclined to do so.

Please understand, if you choose to work past this, it will take time. The feelings aren't going to disappear. It will take a long time for him to rebuild what he has damaged for you. While he's screwed up, if you choose to work past this, you owe patience to him as you rebuild as much as he owes you honesty.

Please know I am praying for you. My heart sincerely goes out to you. If you need me for anything, please consider my PM box open at any time.