Allowing the other relationship took a lot of your "fire" as your wife calls it, and put it over with the OM. This is how it happens.
On starting the party back up. As a man, I like to enjoy life. I can dial it back a bit and more stable for my family, but also I don't mind us having fun within reason.
If the wife completely blows her committment to me, as yours has, I believe we should start our party back up. Sometimes we just have to show them, what they are doing is not special.