It also has a voyeurism tag. And again there is no LIs here so ntr ain't possible. Harem is just the most fitting description of where the mc is. It doesn't mean they will worship him. Hell some are with each other.
This is not a romance vn people.
Ok... Let's start from something very simple. From this site's thread of tags and rules:
Voyeurism [Spying on people engaged in sexual behavior including stripping.]
The MC isn't spying on anyone, he's just listening to a story, so that scene has nothing to do with voyeurism. The tag is probably there for the second part of the explanation.
Now about the NTR aspect. I never said there was any involved, so is there a specific reason you're thowing that in your argument? I really hope not.
I called the MC a cuck, which is not the same thing. He is getting aroused
imagining (again, no voyeurism involved, unless she filmed the whole thing and had an invisible projector with her) a woman he knows is willing to have sex with him (if you don't want to call her a love interest, you can call her Bob, she's still someone he finds attractive and wants to bang), taking part in an orgy and thinks someone else's cum on her face is "hot". He can bang her, but he prefers to jerk off to that thought. How else should I call him?
Lastly, about the harem part, you can take that to dev. The fourth word in the game's overview is the word
harem. I didn't write it and neither did you. You can clearly see the dev has the ownership of this thread, so if they chose to start the description of the game with the sentence "This is a harem themed visual novel game", that means that's how they want to "sell" it. Plus the MC is already flirting with some of the women and taking into consideration he's too damn slow to think he's doing that just to achieve his goal, I wouldn't call it just a "fuck em all" type of game. Yes, some of them are not very fond of him (to put it lightly), but he only needs 3 out of... fuck... I don't even know how many women are in this game anymore, to call it a harem.