AITA For Wanting to Poop Alone

I asked my husband to take our 19 month old with him this morning to drop my daughter off at school. I asked him so that I could use the bathroom alone. Every time I try to poop my son either screams outside the door or wants to sit on my lap. My husband took him and ran into traffic. Roads closed, trains stuck, etc. Until they were driving for an hour. My son wasnt happy about it and screamed the whole time. My husband gets home and starts screaming that it's not fair to our son that I lock him in a chair in the car for an hour so that I can use the bathroom. He says I'm the asshole because our son shouldn't have to deal with that. I replied that I guess we can't take our son anywhere anymore since he's noy allowed to be locked up at all. AITA?