I'm guessing that's not what you wanted to hear. People come on here to fix their marriages. Some ws' just don't want to change. Not breaking contact, being remorseful, and being willing to help heal are key. Absence of any of those are bad news.
From what I understand, the remorse and willingness to heal don't come until well after the A ends. If anything, my WW has become more determined since I found out about the EA. A couple of half hearted efforts early on to break contact, but now I just get words, BS, and spew. My DB coach did say that the A has to burn itself, the reality set in, before the WW will start seeing anything clearly. I get you though, it's like a big FU when they won't stop. I think if mine had been having a PA, I would have ended it and moved out, it took me many months to find out about DBing.
Good luck with it, be the rock your son needs.
-- Me: 47 WW: 35 SS: 17 D: 5 T: 7 yrs Engaged: 2 yrs OEA confirmed: August 17 2016 ongoing since April 2016. OEA continues (with occasional breaks) BD2 - W says will visit OM in Jan 18