But what is the definition of the larger genre we can call non-monogamous relationships?
The context of the thread was NTR not non-monogamy.
The NTR family doesn't represent the whole thing, but it's a subgenre, but there are elements that differentiate it from others: Humiliation, and it's not just verbal, it's behavioral, social, and visual, even if indirect, it's there.
Humiliation does not differentiate it from others, it a trope added to
some of the works in NTR's sub genres. OP is trying to use humiliation to define
all NTR, which is incorrect. It's like saying humiliation defines BDSM, which would be incorrect. Even through there are
some elements of humiliation in
some forms of BDSM, it is not what defines it, just as it is not what defines NTR.
You mention verbal, behavioral, social and visual? You just described ALMOST all the aggressors / those "stealing" the LI's.
The delinquent
The ugly bastard
The boss
The shota
The ex-BF
The co-worker
The "Jock" Student
The otaku
The "senior" / Senpai
ALMOST all of these fall under verbally, behaviorally, socially and visually shameful too and it's not just the characters, their actions would be / are considered shameful too.
Or the MC always having a "small" penis (in the game world, since all the other characters have larger ones) is no coincidence; the MC is sexually inferior.
While I covered the whole, you are tailoring your examples. The MC does
not always have a small penis, there are in fact many games, stories, clips / videos where the MC has a normal penis or you never see it at all. Your example does not take this into account.
In our culture, it's still seen that a woman's pleasure is the man's responsibility, and a large penis is a source of pride, a small one is a source of shame.
...and therefore having a "normal" / "average" sized penis is not a source of "shame". In "our" culture, it is also frowned upon / condemned to use force against a woman for sex. In
ALMOST all NTR having a "large" penis is not enough, which is why those "stealing" the women / LI's need to use blackmail, drugs, hypnosis, potions, rape etc.
You will also find in many NTR works the protagonist / MC has not even had sex with the LI.
You will also find in many NTR works the LI has not had sex before.
Remember we are supposed to be covering ALL NTR, not just a few works / some content.
Netori and the role reversal, where it's the MC who is humiliating him.
Again, only featured in some works, in many the husband / BF / potential LI has no clue.
In Japanese, the original term and its most direct translations are used. (In Japan, the term is already classified as having undergone Westernization, both for commercial reasons – sales in the West – and for a cultural return of the term, being represented as the Western version of the NTR writing and not 取られる).
Which then opens it up to multiple definitions depending on the community, group, person and their interpretation of it and their representation of it.
Is it NTR if there is a FMC?
Is it NTR if the MC sleeps with multiple women first?
Is it NTR if the LI sleeps with another women once, the MC never knows and the MC and LI stay together happily as a couple?
etc. etc. etc.
Then you get people using NTR for all and people using NTR, NTS etc. and disagreeing that NTR is all. etc. etc. etc.
And honestly, the Japanese definition or any other external one doesn't matter much to me; the community here is already big enough to stand on its own two feet. Current generalizations are bad for everyone, except for those who hate or love NTR.
No generalizations are bad from those who hate and love it too. If you play a game where you steal the next door neighbors wife that is still NTR (netori), if a LI has sex with another women in the harem
some people will loose it and cry NTR.
At the end of the day though, humiliation
does not define NTR, it is not the sum of all it's parts and the OP is incorrect.
If you're looking for a partner swap experience, searching here is a waste of time and you'll find it mixed with Netorase/Netorare; the vast majority will involve cuckolding, humiliation, and SHP.
There are many good sharing games both MC and FMC, there are also many games with different routes so you can avoid the netorare / netorase etc. You should start with come home, it has something for everyone.
https://f95zone.to/threads/come-home-v9-19-16-premium-r-j-rhodes.54521/
The story's conclusion is the grand finale, an important part of the story, and you yourself contradict yourself when it's not in the story. If it were a simple cheat or Li marrying another guy, it wouldn't even be in the game.
Not sure if it's that I haven't had enough coffee yet but I don't understand this part.