Ex Partner comes to see our our 3dc at my house on weekends mostly Sundays, I have posted before that he will only have them at my house but that's an ongoing issue, I have bought an extra armchair that fits/matches perfectly into my home, anyhow today ex partner walks in and sees it and starts shouting 'what the fuck have you got another chair for? You are not right in the head, you have lost the plot' storms off into my kitchen leaving me bewildered and off he goes slamming the front door 
Am I missing something here? Why could anyone be so angry over that?!