At the end of the day, yes Aiko was basically forced into sex, and yes she is in a sexual relationship with the youngest. However the forced sex was unavoidable, both are main LI's and not seeing other men. So it could be seen as NTR and at the same time not. At this point it doesnt really matter since this game has gone so far down hill that I doubt it ever recovers.
We as players as well as the patreons have been begging to take this back to a VN style, never gonna happen. We have been asking for actual content...well look at what we have had. We also have asked that if this is going to stay sandbox give us a hint system...well look where we are.
This has been out long enough that there should be content with the three main girls ( or 4 main if your into Aiko ). But everything has been....to this point fluff, night creeping and or forced sexual contact with others while the MC character watches.
Until things change, us as players and on this forum might as well just buckle up for the long ride of new players and returning ones complaining about the same thing we have all brought up to many times. This has become a joke. End of the day thats all this game has become and no likely fix or return to glory in the future.