Freedom! There is a conversation in May's thread about affairs saving marriages. X's affair saved me FROM my marriage. Lol.
I had to look up 'dark triad' and all I can say is that the above is so true for you!
Sounds like you are such a good mama, S2 sounds darling and well-adjusted. FWIW, my kids also don't ask about their dad or ask to call him when they are with me. It is very much an 'out of sight, out of mind' situation with them towards him. And he is trying to be a very invested Dad.
It goes to show that the investment we make with our kids does pay off. And in the end, we can only control our relationship with our kids; we have no control over their R with their Dad (assuming that we are neutral, kid-forward and not vilifying Dad to kids etc). In the absence of harmful behavior, abuse, etc, I am learning that it is best to let H navigate his own R with the kids. I can only navigate my own.