very insightful... I agree, incest feels interesting and spicy when it's not just ""flavor text"" essentially, like the characters do stuff that make them feel like they are related before sex happens and then you see how the characters are actually worried, not surface worried actually! worried of what's going to happen now that they have committed incest.
let me give an example using your example of what you said, in the case of a brother and sister for example is alone in a apartment for let's say??? a month? and the game takes place in that month and around halfway through the month the brother and sister finally commits incest and have sex with each other.
and in the beginning they are very worried and very tense but then they start not caring as much about making love to each other.
but then around let's say a week before the parent return? we see them trying to think of what to do essentially and in this specific setting, the ending would be determined on how well the siblings are able to basically hide what they have been doing in that month or if they're able to convince that parents to accept their relationship or thirdly! fail in either option, which would also give unique ending.
That would be an interesting scenario to see in a game one day, I do however realize a problem with this and my previous thoughts: The average consumer of NSFW games is not actually interested in a good narrative or game, at least in far as it prohibits easily accessible porn.
By that I mean Developers of erotic games have to be careful if they wish to do more than just make quick masturbation material, if they want a good narrative around the erotic elements then that usually means more time is needed to access those elements and this can easily get frustrating, I've seen this manifest as copious grinding in more mechanically focused games and walls upon walls of text in other ones.
And since I usually find reviews more interesting than the actual games, I noticed that this results in complaints along the lines of "I wanted to play a hentai game, not an RPG." or "It seems like the developers wanted to make an actual game but tacked on Hentai elements afterwards". People seem to feel tricked if the amount of Game or Story outweighs the amount of Erotic elements, even if the Game or Story ultimately adds to those Erotic experiences by providing narrative weight or further context. (Exceptions of course exist, I see the rec thread about Porn games with actual gameplay.)
So I think if a game that properly explored the taboo nature of Incest released, in a way I'd find ideal, I doubt very many people would actually enjoy the game since it would have a long "build up" phase. This would be even more so of a problem if it were released in chunks over an extended period of time, example being Sinful Summer.
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Taboos are social, not legal. There's a reason people like M/S B/S and F/D incest more than first cousin incest, despite all of those being equally as illegal in most places. The closer the relationship, the more socially unacceptable it becomes, the hotter it becones.
This is quite true, there is actually quite a fight in academia over how Families work and to a lesser degree what is considered Incest. I've seen some arguments between professors about this topic, it's quite interesting.
The war is between Biology and Anthropology, the question is: Are the way Human family units structured a Biological phenomenon, or a Cultural one? I personally think it's almost entirely cultural but with enough biology thrown in there that it muddies the water.
Anyway, we are talking about Incest.
What is considered Incest is actually remarkably fluid and almost entirely divorced from how closely blood related you are, the genetic inbreeding argument is a modern one and not actually how things work socially.
The taboo is dictated by what is considered the same as you (Endogamy) and what is considered different from you (Exogamy). What is counted as which is heavily dependent on the Culture and as much as Modern society would like it to be, close relative relations are more common by their standards.
As a tame example, in some parts of the world it is considered perfectly acceptable to have sex with your 1st cousin. In other parts, it's completely abhorrent. This is the most common variance you will see in modern western society.
As for more extreme examples, it's not uncommon for it to be acceptable to marry your uncle or aunt. Mosuo in China do not consider the Father to be part of the daughters family, so it would be perfectly acceptable socially for them to reproduce with each other. In some cultures, having sex with a close family friend would be considered as incestuous as doing the same with your sibling.
Though the thrill from breaking Taboos is ironically universal and the more the other individual is the "same" as you, the bigger the Taboo and thus the Thrill.
This quite got away from me I realize, it's rare I get to talk about these topics. While it's not strictly off-topic, I'll try to not make a habit of writing small essays.