OW's H is part of the problem because he is also getting the best of everything. OW won't divorce him because they have too much debt, and she lost her job so she has not way of getting insurance and with no family close by, no one to help her out because H doesn't have extra money to help her pay her bills. So he still gets his wife, but if they fight, he ships her to my H who calms her down, and then when she is "happy" again goes back to her H. OW's H gets to go out and drink (he has a drinking problem) with his buddies (works at a college) then goes home to W and if she isn't there he knows where she is and that at some point she will be home. In that aspect, H is being played too, but he doesn't care.
Okay so this is about as dysfunctional as it gets. Unfortunately, not only are you having to deal with a messed up H, but he has gone and gotten himself into a R with an even more messed up couple. I would suggest you go EXTREMELY slow about any type of reconcilliation. Ensure beyond a shadow of a doubt that your H is sincere about reconciling the M (if that is what he implies he wants to do). Also, EXTREMELY important that you ensure he provides proof of no STDs prior to resuming any type of physical relationship with him if you do move toward reconcilliation. Stay strong and focused on what you want. IMO you are the only sane one in this group right now.