Classic erotic book suggestions

I was reading this book where the main character introduced me to Delta of Venus by Anaïs Nin, I decided to give it a try and honestly I kinda liked it.
I want to explore the genre more so I google searched and let’s say it was useless.
Can someone please suggest me a proper erotic classic. I am NOT looking for porn. Reader’s know the difference between porn and smut.

by nextdoorlibrary