I [68, F] decided to write a letter to my only son [45, M] who did really terrible things and he will soon die for it. What should I write?

There are no rules for this. You should feel free to say whatever is in your heart. You should also feel free to simply say that your thoughts and feelings are too complicated, but that you are thinking of him and will always think of him.

For you, personally, let me say that I am very sorry for the agony you have experienced. Sometimes, things happen that are too horrifying to imagine, but I hope that you find some peace about it. Your son is your offspring, but he is not you. Take good care of yourself. On the day your son meets his end, try not to be alone. If you have no other options, at least schedule therapy for yourself for that day.

/r/relationships Thread