Sex really must be understood to be about other things than just seeing any nudity at all. Our natural selves do not have that power without further context. The other contexts will not disappear.
Back when I was involved with AANR (American Association of Nude Recreation), and President of an AANR affiliated club, I became aware of inside goings on. Despite all their rhetoric about being asexual nudists, most AANR affiliated clubs had "secret" sexual sub groups of "swingers." My wife and I didn't participate, but after we got divorced they invited her to join.
Humans are a very sexual species. We breed slowly, and children take a long time to grow up, but we didn't become over 8 billion by keeping our bodies apart. It's a very powerful evolutionary and biological desire for most people, especially young people.