"Most kids in the UK don't have religious parents these days, or have much exposure to religion. Yet they still become fascinated with sex and nudity. "
My Finnish old girlfriends would roll their eyes and say "Typical English". They have been Anglophiles for over 50 years - but instances of the British equation of nudity = sex still really annoys them. In Finland nudity is taken as natural. Sex is something you do with someone with whom you form a particular relationship.