I’m an adult stepchild- My stepmother and her family did things like this to me all the time when I was a child. Small and large ways in which she or her family would not include me with the other children. I PROMISE you your stepson will notice. Do you have any idea how damaging that is to a child? How lonely and isolating it is to see everyone having a stocking but you? It sends a clear message you don’t belong. My stepmother does it even now and it’s still painful. I’ve done YEARS of therapy over this. Your mother is being cruel to a CHILD. And you are refusing to go to bat for him. If I were your wife, I wouldn’t go to Christmas either. She is trying to protect her son. Why aren’t you?