My father turned the tables on me with this sort of thing once. He had then-infant DS1 while I ran a few errands, and when I got home, there was my dad standing over a screaming DS1 trying to change his diaper. I offered to take over and asked "What did you do?" -- meaning, what have you tried so I could either avoid aggravating him or try something new -- except it sounded waaay more accusatory than that and my father countered with, "I held him upside down by his ankles for a while, what do you think?"
Since I was a SAHM and my parents were five minutes away, most of our sons' time was with family. When we did go elsewhere, though, our neighbor's middle school son stayed with them (they were early elementary school age by this time). He was so conscientious, took classes to prepare, oldest of their four, and a lot of fun. They were playing outside when he noticed some door-to-door solicitors going around in our neighborhood and he called his mother for backup.