I'm not sure what to say. I've read through the conversation today and it's so nuts. I understand the need for forgiveness and letting go, in fact I whole-heartedly agree. As MWD quipped, Forgiveness is a gift we give ourselves.
But forgiveness is for past injuries. And for injuries to be in the past the injury has to have stopped somehow. At no point does that mean the injured party has to subject themselves to more injury -- and it certainly does not mean they have to trust the offending party. Trust only comes when there is some degree of reconciliation, and reconciliation does not even begin to any degree until both parties agree to bury the hatchet and forgive each other. Again, they still do not necessarily have to have even a friendship at that point. But there's no reconciliation in any degree if one party continues to injure and maintain hostilities against the other (for either side.)
Personally, I believe Donna is fully within her rights to not trust the ex and his A partner. There has been no contrition at all on their part. For that reason I do not feel it healthy in any way to pretend the situation is otherwise, even if it is the pretense of making peace for the children. At best you have a detente, but Peace it is not -- and no one is well served by feigning otherwise. Everyone can and will see though it anyway, even the children.
The healing in forgiveness is that it allows us to cope with the injury and continue with our lives, but it doesn't mean we continue to expose ourselves to people known to be a threat or to have no conscience in seeking their own selfish ends. It is only natural for a parent to hold reservations about your children being exposed to people with such poor character. And while there are circumstances where we just do not have any control over who has such access to our children, by no means should we be expected to like it much less embrace it.
If I manage to survive the bite of a snake, I might be able to forgive it, but never trust it. If it remains a threat to me and my family, I will take measures to protect myself and my loved ones. Wisdom merely dictates that I not allow the past injury to wreck my life going forward, to learn from it and move forward. To forgive but not forget.
But the advice I hear given to Donna is alarming. And I shake my head at the veiled assertion that Donna has somehow been a terrible person for not embracing people known to be treacherous. I don't get that -- we're not supposed to "assume" the adulterous waywards were anything but innocent star-crossed lovers who meant no one any harm, but somehow Donna is the offender for not accepting them with open arms? Somehow she is the one who is thereby harming her children?
Again, I understand the power of Forgiveness to free ourselves from bondage to past injuries. But this is going a bit too far.