The scene in the first few minutes in which young Therese writhes on the dirt and watches the shirtless thresher is the most frankly erotic moment of the movie and it is all downhill from there. It is a sordid movie and very unpleasant because the central characters are crude and uninteresting. Since erotic hunger is the motivating force of the film - bad idea to have your most memorable erotic moment at the start.
I totally agree with you. That scene in beginning was very powerful and erotic. I was expecting similar scenes for the first third or even half of the movie. Instead, we seen her just hook up with the guy early on the movie in very generic love making scenes. It's what they don't show and don't do that makes it a more powerful movie. I thought we would see her spy on secret crush a few times and have some more "self pleasuring" moments. We didn't get enough of that. The nudity was awful and non-existent as well. Not that a movie needs it, but in this case, the subject of the movie is sex, and she had a full wardrobe on half the time. The scenes were just pretty bad and unrealistic.
I read somewhere that one of the biggest turn offs to modern women is odd facial hair. I wonder how many of the ladies dug those 'sideburns gone crazy'.