I just find it interesting that now that I have become so indifferent, that it appears they are really breaking it off this time.
You aren't indifferent Ken, you are detached. This is what we've been telling you to do for months and months and months and months...
Once you detach it is a LOT easier to combat an affair and a wayward partner.
I wouldn't count my blessings just yet. However. I doubt your wife will pursue divorce. She may start the process, but it does take some time and she has children to think about. I can't imagine her going it alone Ken, she's way too immature to do that.
And telling OM "Thanks for ruining my life" is NOT helping your situation.
"Stay away from my wife you sleazy creep" works a lot better.
And your wife or you not finding anything with a background check does NOT mean he's safe around children. It just means he hasn't been CAUGHT and CONVICTED. If he's THIS bad around adults can you imagine how he will be with kids? Do you think someone this selfish and manipulative should be parenting children? Even as a step-parent he would have a lot of influence.