My mother in law left my 4 year old son alone in the car while she popped into a shop to get bread the other day. She did this because he was having a "strop" and would not get out. Apparently she parked right outside and only had her eyes off him for a "minute or so"
I personally find this unacceptable and think there is no excuse at any time for a child to be left unattended in a public place. Am I being unreasonable?