On the one hand, I am sorry to hear you are in the situation of deciding to follow through on your conditions for R. I think many of the previous posts clearly indicate a majority of people side with dumping his a$$ to the curb and that his A was not definitively ended (kind of an open ended closure to the whole thing).
But, on the other hand, I can empathize with you on the difficulty in following through. On DDay#1 I made it perfectly clear that WW was to NC the OM. DDay#2 was a few months later. I repeated my conditions for R with WW. DDay#3 was 2 months after that. All three DDays resulted in my wife stating that it was her belief that "what I didn't know, couldn't hurt me". And that she never intended to leave me nor intended for me to find out. In counseling over the last 10months, it has become perfectly clear that if allowed to maintain both her stability with me and her fantasy world with the OM, she will find a way to make it happen.
I agree with those of you who advise to send the WH packing. If I had it to do all over again, I realize now that I should have done just that. Now it's just a matter of time until DDay#4.......only this time around, I'm done. There is no reconciliation after DDay#4.