You keep using that word. I do not think it means what you think it means. -- Inigo Montoya
Unless your mc is there for the act to be humiliated or unless your mc has a relationship and is cheated on, it is not ntr. People use that abreviation for anyhting where another male has action anywhere, it seems to me.
(No, I have not played the game. I saw a far worse word. Kinetic. And to me, that makes the game more like a movie and your mc not your toon, but the protagonist in a story. Wich would make the tolerance for alleged ntr even greater, as you can easily change perspective in a story. It is just stuff that happens. And it would actually make the player the cuck, because they have to watch how the protagonist gets some. But do not tell the "ntr" haters ;-)