Your answer tells me you do not know the distinction as hotwifing as you call it, is basicly Netorase which falls under NTR.
A moment ago you were scolding me for conflating netorare, netori, and netorase under the blanket acronym NTR. Now you're doing it yourself in an apparent attempt to contradict your initial argument. Weird.
But you're right: MC-encouraged hotwifing (or Anne-encouraged hothusbanding, if you will...though that only happens once) should be netorase, and thus it's true that there's NTR in the game. I'm guilty of assuming that people looking for (or looking to avoid) NTR have the emotionally-laden type in mind, not just sleeping around. I guess that's a bad assumption, considering how many people see their designated lust objects touching another man and freak out about NTR on the forum...
That said, this is actually a core distinction between this game and others like it: the MC's wavering between enthusiasm and indifference towards Anne's cheating. Yes, at times he's a "willing cuckold" if that's the definition of netorase that you want to use, though I would actually claim
that word is almost as misunderstood as NTR, and that it doesn't apply to most of the MC's feelings regarding Anne's extramarital sexual activities. If we're going to be as strict about the definition as we are about netorase, cuckolds aren't willing. The MC's desire for Anne to fuck other people because he gets off on it largely disappears fairly early in the game. Not long after the vacation, actually. That's the point where the narrative starts to be much more driven by Anne's choices, even though the MC thinks he's still at the wheel.
The MC's emotional journey is one from enthusiasm/arousal to casual indifference, and I suspect that's by design because Anne's actions eventually reflect that indifference. I find it very difficult to call the latter netorase. It's more that he doesn't care...not just about the sex, but about
Anne.