seprated 5 years and divorced 3. Ex had multiple affairs which I ultimately found out which completely shattered me. Co parent 50/50 our 7 year old son. Since I bought my own house and moved out of family home I have not let my exH into my home. This is my house and my sage space. He continually says I’m unreasonable.yesterday morning he came to pick son up for school and son had built a fort in the living room that he wanted to show his dad. I heard son ask dad to come in and dad said to ask me. I said no you’re heading out to school now and I’m going to work and dad doesn’t come into our house. Son then said but you came into dads last week (I did for first day of school) but that’s up to his dad not me. Son got really upset and I understand to him he just wanted to show his dad the fort but I don’t want this man in my house ever. Not only did he cause me deep heartache he also continues to cause issues with co parenting/ childcare/ new partners etc that I just don’t want him in here but I can see my son does. We don’t spend time together as a 3 ever and im happy with that.
aibu to hold firm my boundaries on this? How should I explain this to my son?