gonna be honnest and say that, despite the tittle having ntr in it this so far has been anything but and ntr or a very diluted one at least, the guy doesn't actively cuck his friend, he's just smart as fuck and not a virgin like all hero protagonists are, even the guild lady was having a thing with the other woman and was taking advantage this whole time of them, of course this can very well change in the future if the protagonist turns into a cunt, but so far he's just been a really smart good guy, it's not like he hates his friend and only takes advantage of him he's protecting him in his own way