You should reflect back on that “less prude than Americans” part of his statement. It’s only “not really possible” because of widespread American taboos about nudity. If boobs were visible in everyday life - on TV shows and at a typical day to the beach - in a non-sexual way, your son wouldn’t give a crap.

It’s interesting that in many US cities, there’s no law against women going topless, but if a woman does it, it’s outrageous. Hell, some women get chastised for breastfeeding in public. We’re a messed up society.