Therese and Isabelle books
The first version is paperback, 96 pages, 1966. This edition has 8 pages of photos from the movies. The text is divided into chapters.
The newer is also paperback. It's 246 pages long. There are no photos. There is, though, a section on how the book was censored and an afterword with books cited. There are no chapters in this version.
The story is about two girls at an all-girls school in France. They fall in love and manage to find a way to have a sexual relationship despite all the other people in the school. The books devote a lot of their time to the sexual relationship. They do have problems but their relationship, both love and sexual, does seem to survive but something happens suddenly that ends everything.
A movie was made from the book and the movie was quite good.
There's a lot in the section on censorship of the book and how it was originally to be part of another book but was removed by the publisher.
The story is highly sexual but it's also very focused on the feelings of the two girls. The language in the 1966 edition is a little flowery for me. The 2015 edition is translated by someone else and the language is much more realistic.