That sounds really tough about your S, it's good that you are his foundation. I have a friend whose parents D when he was a young teen and it was really rough for him and his siblings. Both parents went off the rails and it catapulted him into adulthood. He said while he is grateful that he grew to be a stronger person it took him like 15 years before he could reestablish a healthy R with either parent. I am definitely worried about the outcomes and actions of my children due to this. D5 hasn't reallly expressed any emotional outbursts, but it is bothering her. She asked my Mom yesterday if she was going to D my Dad or if my in-laws were going to D because that will make her sad and D is a sin. This morning she was crying and said she didn't know why the tears were coming out of her eyes when she isn't sad. IC said even in the best sitch to expect some freeze in child development. Unfortunately in this sitch there are no winners.
I had a good friend whose mom cheated on and left his dad for the OM when he was about 11. He never has truly forgiven his mom. His dad passed away several years ago, and he to this day has zero tolerance for anyone that would cheat on their spouse. So while it will be rough for your D8 in the short-term I predict that you two will be very close for the rest of your life.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018
