I would think that your H already knows S is sad because of the situation. When you text him like you did, you are trying to put a guilt trip on him, and we know that doesn't help matters. Try to text H about a pleasant subject, give him a reason not to dread contact. Stop showing your bitter side to him. My H never knew our S knew about ow. I have never told him. Their relationship has improved so much. Why not ask your H to help recommend a gift for S for Christmas. Is it even possible for you to let go of your resentment and anger long enough to do this?
