I love the first "sex" fantasy that I remember: I couldn't have been more than seven. It involved a girl from school that I had a crush on and me crawling along a series of mountain peaks in the same way one would traverse a picket fence.
And she was naked. Nothing pubic. Had no idea pubic hair even existed.
I didn't know the first thing about sex or how nudity was involved or anything else. You've got to understand the era. Before the late Sixties, it was more than possible to live an entire life without brushing against either a movie or a book that couldn't also be shared with a child. I sincerely doubt that either my mother or either of my grandmothers ever saw anything X-rated.
I haunted our local Salvation Army for Hardy Boy books, a dime apiece, three for a quarter, and that's where I saw my first nudist magazines, there with the used copies of Life and Saturday Evening Post. Black and white photographs in these magazines, and plenty of them. I can't remember whether the women's nipples were airbrushed into a blur, but the penises and vaginas definitely were. Bare butts, not a problem. People danced. They had picnics. They hiked and swam and played tennis and badminton, everyone smiled and looked happy at all times, all without clothes on.
I couldn't compute what I was seeing, but it sure intrigued me.
Still does. in a way, although, at seventy, that's fading fast.