I am sorry you find yourself here, but know you have found a safe place to vent, with people who understand your pain.
She's still having an affair with him, and as long as he is in your life AT ALL, you will never move forward at all.
That is certainly what everybody has to weigh, but it is not good for the family if mom is seeing someone outside the marriage and dad is being tied to an emotional rollercoaster. Good for the family may be you telling your wife you just won't live this way anymore; it is not healthy for you or the family.
I have been on this board for two and a half years, and have seen many times, the experience you are going through, not to mention the fact that I have experienced the exact same thing myself.
The place you are at right now is an all too familiar one.
I'm so sorry this has happened to you Kbz .... I don't think I've been much help to you.
Keep posting here. There's lots of people who are going through the same thing, and who are much better at putting it into words than me. You'll receive lots of support, so you've come to the right place.