For those who provided me such great input on the "Confronting the Other Guy" topic over the past week, I really appreciate it! I told you I'd provide an update on what I decided to do, so that is below if you're interested.
I chose to confront the guy but had not made up my mind on whether I'd tell his spouse. So I had a phone conversation with him that went fairly well (given the heavy nature of what was being discussed). Since what I had 100% confirmation of was an electronic affair, I told him he needed to delete any communications/pictures they may have exchanged and continue to have absolutely no contact with my wife in any shape or form. He agreed to both. We talked about other things as well, and I told him he needs to step up and confess to his wife what has happened as she is the only one in the dark. I told him I have not made my decision yet on whether I will tell her, but he has an opportunity to be proactive on this issue. She actually is in counseling now and he told her he doesn't want to do it. Amazing. So I told him that that was a big mistake as well and that he should man up and join her in counseling; it's absolutely ridiculous for him not to do that. I doubt he will of course, but I informed him that this is a big mistake particularly since he is the one who was being unfaithful.
He said that if she finds out, then a) everyone will know (including both sets of kids and all the sports/school groups), and b) his wife will divorce him. "B" is not my concern, but THE WELFARE OF MY KIDS IS MY TOP CONCERN. When explaining this conversation to my wife afterward, she agreed that if the other spouse finds out it will become common knowledge. So that puts things in a tough situation for my kids, I do not want to have this be public knowledge to the kids and their friends/family.
As far as he is concerned, he does not know whether I'll be informing his wife about the affair. But I probably will not be telling her because I want to spare the kids the agony; I'd much rather bear this alone than have them feel even a fraction of the pain I'm going through. Morally, I feel badly keeping this information from the other spouse, but my kids come first.
So that's it for now.