what to do next..

[Terapin]

You're exactly right. You can't control what she does, especially at work. Don't even try.

You're also right that even if it's 100% guaranteed that she stops the affair, it's going to take years to build back trust. So again, regardless, this is going to be a long process.

It's good to have boundaries with her, but your boundary of 'just don't be with him around me' reeks of weakness. You basically gave her permission to continue the affair, as long as you don't witness it.

IMO, do not initiate any 'final talk' with her. The only thing you should say is 'W, I can no longer be married to someone that has blatantly disregarded me, our kids, and our marriage. I have filed for divorce, and I think it would be in everyone's best interest for you to leave the marital home'. You say nothing else. No ultimatums. Ultimatums are weak, especially if you don't follow through. You need her to believe that you have had enough and are done being disrespected. But the key here is, it has to be true. This isn't a secret ploy to get her to stay. You're done, finished, and moving on.

Again, there are two possible outcomes of this. She either agrees to divorce or she fights for another chance. Neither of these outcomes will likely happen immediately. So in the meantime, you do all the 180, GAL, etc as you continue to proceed with the D. Like you said, D is a long process. You can stop it at any time if you choose.

Remember, she has cheated. She's the one that's caused all of this. So if D does happen, you will never be in a better position to come out of the D unscathed as you are right now. If she does commit to the M, we can cross that bridge later on.