I am away this week and have left teen ds at home alone so he could attend school. He has stayed home alone a few times before and is happy with the situation. My ex was planning to pick him up in the morning and bring him to the school bus, as it leaves 20 minutes away from the house. I have just found out that my ex stayed overnight at my house while I am away, without asking me. I am not at all happy with this but don't know how to respond. Any advice?