At home. I admit I wouldn’t want him scarred by possible ridicule from kids and other people. And sometimes there’s much less to this sort of thing than meets the eye.
When we were kids, my brother (who was about four, I was nine) started carrying my purse around the house.
Our father was horrified, but to her credit Mom told him not to make a big deal about it. They got my brother a bag that was gender-neutral and suggested he return my purse to me.
When I opened the purse, he had been using it to transport his green army men ! So he was perfectly happy with the alternative they offered him.