How horrible. I'm sorry your Ds and you had/have to go through this! The only comment I have is not to confront the OW. It won't change anything and you may feel foolish afterwards.
I have no idea what the correct thing to do is, but I would do this: decide what your boundaries will be NOW: I would think they need to be adjusted at this point. And I would tell H exactly what you found, your new boundaries and why. Then stick to them no matter what. Keep emotions out of it, just very matter-of-fact and that should include objective descriptions of how your Ds found the evidence. I think the fact THEY now know the horrible lies he's been telling will impact him more than the fact you know the truth at this point.
Hang in there.
Me: 39 H: 45 Second marriage for both H left 12/2013 M:4 T:5.5
