It's not NTR, not exactly. But it's his Mom, screwing the guy who knocked him out. That she also calls him a loser like his father is pretty harsh. The fact you can't avoid seeing or fast forward past it made it even worse. You could make it obvious that this happened without making your audience/readers witness it for such a long period of time. If you wanted to add a sex scene so early, perhaps you should have done something with the MC and the nurse instead of having him run away.
If your goal is to make the MC (and the player) feel humiliated, then that was a good way to do it, if that is your game, fine. If not, I would recommend changing that scene. Shorten it, maybe just show the MC listening briefly and figuring out what is going on. NO reason to make it such a long scene that you can't skip.
Only my opinion, it's your game. At the end of the day you got to be true to your vision of it. Unless you are trying to make money and be popular, then sell out, LOL. I think it has promise. Your suffering the thing another really good game went through when he added a scene where one of the characters wound up randomly having a two way in front of the MC. It wasn't really NTR, but he wound up removing the scene but he took a lot of abuse from it. It's a really good game though.
Your models are good, your English is not bad. Could use some cleanup, but so much better than I could do in most other languages.