Quite often I'll nip into a shop on the way home from a day out. My son is 9 and loves reading. Recently I've been leaving him with his book while I grab the shopping with his little sister. He can be trusted to do nothing but read and it's only 10 minutes. AIBU? My other dilemma is whether to leave car locked or unlocked or locked but give him the keys. So far I've locked him in but left a window open for him.