I have many small variations of the shower masturbation scene and in one you can't prevent the masturbation . Same thing for the classroom scene. You can say something about anime, games and nothing intrusive at all, but that all depends on your earlier choices.I have noticed that the main character seems to get intrusive horny thoughts. Like when one of the first things he thinks during the introduction is how much he appreciates women.
And those seem to optionally get worse.
My first playthrough, I went with Anya at night and he seemed to have some intrusive thoughts but not many. My second one I went with Jane and he seemed to have much more intrusive thoughts like that. After the shower in the morning, the game didn't even give me an option anymore and the mc automatically masturbated.
Then when I reached the introduction in the classroom and went with the "be nice" choice the mc completely faltered and after giving his name had so many intrusive thoughts that he couldn't come up with anything about himself apart from liking women and claire eventually just moves the class along as the mc can't come up with anything to say.