I will leave you in Gucci's more-than-capable hands as to the particulars, since his advice is playing out precisely as you want it to (and as he predicted). But I just wanted to say this:
If this goes according to "script" (and they usually do), then not only would I agree with whoever said that your BF has NOT told the OW that he's trying to reconcile with you, but that he is PURPOSELY going to try to move Heaven and Earth to make sure that at least ONE of the two "dishes" stays spinning on the end of his two "sticks."
I think he's terrified of losing BOTH of you (which of course is what he really deserves), he KNOWS he needs to end it forever with OW, but he's afraid to do so unless he knows you'll be there waiting for him.
Unh-uh -- doesn't work that way. He has to burn THAT boat behind him, FIRST, as the price to even get to play the hand with you.
You're in a tremendous position of strength here. Play your remaining cards wisely.
- Puppy, who just mixed his poker and his naval metaphors