Well I do not know what you did wrong or just did not progress far enough in your game, but going negative with Nicole does give a totally different end of the game.
Just if you go negative she will for a time pursue you more aggresively.
Considering the incest thing, well I think the direction of the game and its intention was clear enough from the start,the fact devs or an insidious uploader
needed unfortunately to use a workaround to make the game they wanted due to unwarranted censorship of a company does not take away from that. I get you are not a fan of the genre but that is your problem, not of the game, it delivers what it says on the package. Only fault is that the cleaned up version may not be cleaned up well enough as they intended to stay out of trouble.
*Yes, unwarranted censorship of a company. That content is not illegal by law, it is just the desires of some people in the corporate board of a company that more or less makes illegal what is not illegal and as such overrules the will of lawmakers around the world that at least have some democratic legitimacy.