If this was the same OW as five years ago, and what she said is true (It went no further) it may be that your H has some infatuation with a fantasy (forbidden fruit, so close and yet so far).
Be very careful. You need to be in control of yourself. That is why I said heal yourself first.
It is a good sign if he blocked her text. That's a positive that he may be serious about the M. Are you?
Don't let him find out you've been in contact with OW. He'll turn that into a trust/privacy issue for sure.
If you decide for saving the M, is he open to MC or Retrouvaille? You're going to need something IMO to help the two of you work things out.
Once you detach from the emotions and get in control, it is easier for you to become the infatuation. If he wants back, you hold all the cards. Play them close to the vest.
God, I'm rambling! Correct me of I'm wrong anybody.
Me 53 XW 50 M 18 Years +2 S14 D19 Bomb 10-24-10 Served 1-27-11 Mediate 4-21-11 Civil D Final 6-2-11 No church anullment "A man is not finished when he is defeated, he is finished when he quits."