I don't think it can be that painful to want your marriage over. My husband decided it and stuck to it and all the time admitting how much happier he is and and how he can't change his mind not WANT but CAN'T. So it can't be that bad. If I had a choice I would have picked to be a walk away spouse then the one left behind who hurts. hmmm hurt, pain, crying, suffering on one hand.....new relationship with a much younger person, no hurt, no pain, partying with my friends, and wife and child instantly gone in other hand.....I would have to say I would pick hand B anyday over hand A.
Almost makes me wish he would come back so I can kick him out to let him see how it feels.