Most Helpful Guy
Excellent question. I would say:
"When we had problems and we knew about possible solutions, you couldn't be bothered with taking time out to address those things. Your absolute indifference to our marriage is a violation of your marriage vows and you don't even care but you are just as bad as someone who cheated on their spouse. You are a bad person and your parents are looking down and feeling shame for you. The worst part is that I misjudged you so horribly and I thought that you were a good person. Return to Hell, demon!"
I might not say the "return to Hell, demon" part.
Most Helpful Girl
I still love you after a year we were separated by distance. We both have had our quiet times, and we've met our own new potentials ever since then - mine has failed twice, yours is ongoing.
Pains me to know that your heart is with her and not me, but I still do wish you the happiest with her. I can understand why you wouldn't talk about our respective new romances, and even though that's not how I function, I respect that as your now friend.
In all honesty I wish to be in her position - had it not been for the distance separating us..