Our other children forced our son to forgive his grandfather against his wishes

I posted before about how our 16 year old son had demanded that we basically excommunicate my father. The reason was that my father caused an accident that left our son with significant burns 11 years ago.Our compromise was that he would not be made to interact with his grandfather and we will not talk about him in front of our son.Unfortunately, my father found out about our son's sudden change in attitude towards him and he has voluntarily started avoiding us.Our other kids have been on their grandfather's side from the start, which had caused our son to isolate himself from both us, and basically the only friends he has.On Sunday, he broke down in tears and called my father to our house and said he took everything back and he forgave him. My poor father was very upset and quietly sat through it all.The rest of us were really happy with all this until yesterday, when my wife discovered that our other children had forced our son to do this using threats of silent treatment and exclusion.We also found out our son messaged my father and accused him of turning the family against him and in turn, forced my father to come over and be "forgiven".I understand the other kids intentions were good. But my wife and I feel that our youngest was bullied into something he is clearly not over.We are still a no go on the therapy for our son. He has cut himself off from us in terms of any communication.I'm just wondering how we deal with the other kids. We are going to talk to them tonight. Do we punish them?I want our son to at least have them to talk to. I don't want to jeopardize that. via /r/Parenting https://ift.tt/2Nm0Gyy