Found this in another thread (showing what a NTR fan's perspective may be):
To me it shows how limited people's perspective can be when they fall into dichotomy like that. Discussions on this thread have helped me distil what I look for and it never falls into black or white categories. The way you put it, "game that THEY are playing, not where one or the other is being controlled by the other, or by other characters" (while still presented as a dichotomy) deserves its own category, imho. What should we call it? It's not netorase (typically, netorase purists say netorase is about a dominant male MC who pushes his female companion to have sex with others). It can include swinging, but it's broader than that. It implies parity within the couple - cuckold fetish is sufficiently its own thing to be called, well, cuckoldry. Sharing is good, but vague.
I get that my point of view is different from obvious industry "standards" or definitions.
I would describe it best as being considerate of both partner's views, not just the male or female's. And wanting to see both views as equal. No dichotomy. That dichotomy sucks, and just shows a real lack of imagination, for mine.
This is the primary problem I have with these definitions, in that they all only seem to consider the influences being placed or played from the male's perspective, in that "he" influenced "her", or "he" stole "her", "he" enjoys others with "her", or "he" is oblivious of "her".
To me, ALL of the NTR definitions are just male definitions, from the male's pov. And all female-perspective ntr definitions are just "she's a slut" or "she is becoming a slut" basically, but it is still considered as if it is a male viewing and deciding what/who she is. "she" is just a vessel, not an actual character, with a life-view and opinions that are valued. And all "she"'s are always just wannabe sluts really, just waiting to be "awakened". Its a really cynical view, with no basis irl.
I suspect it is a main reason why some can't come to terms with FMC-only games, unless she is just a slut in the end, not anyone's partner, and there is no husband involvement in any of it. (all the No-NTR fans)
The woman is just a side-character really, as far as her being part of the thought processes shown in the game, as she is always portrayed as being part of a male fantasy somehow.
(Not to say that there aren't some great FMC corruption stories out there, but they are few and far between, and usually not a concern for any form of NTR/NTS fans, as in no-one cares about that aspect in those games, because any males are not actual MC's.)
I would actually say that this IS proper sharing that I am describing, and that that is what sharing actually means, because all the "male definitions" don't include "her" viewpoint, whereas sharing does/should. In that, it is not just "him" sharing "her", but an actual shared experience, for both.