Yea, I suppose the spectrum of NTRish tags has a fine line. There are noticeable differences in the character archetypes involved in this, and also for the story telling mechanisms as a genre/fetish.
Wives could certainly cheat on their cuck husbands. Basically if the agreement was only to do it when they are together or always tell the husband about her cuck fucks, and she goes behind his back and just fucks all the time with the bulls and start to just fall for them completely. That said, in a game that is divided into 3 distinct flavors of the "NTR spectrum," it seems like it would be missing the point if the infidelity route just straight up makes the husband a willing and self admitted cuck. It would overlap with the cuckold route too much, essentially making it redundant.
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While I'm at it, let me just do a quick run down of my understanding of this whole spectrum.
True classical NTR - Loved one is stolen by another cock. He is generally weak willed and impotent to do anything about it even if he finds out about it, but the NTR reveal is best served near the end. The male victim does not enjoy this at all. There could be some variation where he awakens his cuck instincts, but this is usually reserved for the very end as well. I'd say the main appeal here is seeing a pure woman fall to some big dick chad through his corruption process.
Mystery NTR - Same as above, but by definition this one keeps the reveal until the very end. The MC doesn't have to be a weak chump, but in most cases, he should be rather weak in bed (comparison of the manliness is a strong trigger for her corruption). The girl does a nice job of hiding it, until she slips up to allow plot progression. The story telling mechanism relies on the growing sense of uncertainty and paranoia felt by the male MC and showing the progressive moral degeneration of the woman if her POV is offered. Maybe this is more of a subgenre of classic NTR more than it's own category.
Getting cheated on - Perhaps similar to the above two, but I'd say the difference is that NTR necessitates the woman being stolen (mind body and soul), while mundane cheating doesn't always have to end that way. NTR also relies heavily on corruption of the woman, while regular cheating stories don't necessarily need this element.
*I'd say the infidelity route of this game could be using elements from mystery NTR and just good old cheating, depending on how it progresses and ends.
Netorase/willing cuckold - This one is easy to understand I guess. It's the most common type of cucky story we see in the west. The MC is a cuck, through and through. He encourages the wife/loved one to cuck him and he enjoys the humiliation and feelings of inadequacy. There could be some variation where he doesn't outright admit to enjoying the humiliation and such, but deep down, he does, evidenced by the fact that he just takes all the abuse like a masochistic cuck.
Hotwifing - I'd say this is similar to willing cuckold, except it's more wholesome. Rather than focusing on the humiliation of the husband, it deals with the sexual liberation of the woman. The husband is very happy that his wife is happy. He will get aroused hearing her stories of seducing other men and such.
Swinging - No explanation needed. You swap partners and everyone is happy and adventurous.
Sharing - Pretty broad. Share your goods for whatever reason. Could have subgenres in here I guess. Prostitution. Male dom type of guy who shares his woman because they ain't nothing but a pussy. Maybe some wholesome sharing seen in open relationships. Threesomes of any kind. Etc. I think this could be a tag of exclusion. All tags the NTRish spectrum is basically sharing with more steps involved, so if something doesn't go into a more specific type, we could just call it sharing.
I think this makes a nice split. The first 3, NTR, mystery NTR, and cheating is undoubtedly dark in nature. Netorase/willing cuck has all parties content with the set up, but it does deal with some negative emotions on the cuck's part (even though he enjoys these negative emotions). Swinging and hotwifing is wholesome stuff with rainbows. Sharing can be anything, depending on the circumstances.
There could be crossovers. There could be situations that start off as one thing and ends up as another. It's actually quite common for most of the more wholesome types to just end up in NTR. Swing and a Miss, for example. Most japanese netorase stories also end up in NTR eventually lol.
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So this game has:
1) Sharing route with an alpha MC (I think). He doesn't feel cucked or anything like that. I think the dev notes said he has bigger dick here? Probably more chad in bed too.
2) Cuckold route with beta cuck MC.
3) The infidelity route. I think the dev's idea is to place this MC somewhere in between the other 2. Not some alpha, but also not a beta chump. However, I still feel like a player who chooses this route is squarely in the NTR camp. If they weren't, they would have picked the Sharing route, right? So I do think the MC should be rather unremarkable in bed in this route. Even if he is a loving husband or a hot teacher for the Debbie, he underperforms in bed so they can't fully be sexually satisfied. The difference between this and the cuck route would be in the MC's disposition. Cuck route MC will encourage and like being cucked. Infidelity route MC does not want to be cucked.
