Are you really that stupid (we explained it a lot right now) ?
Open path allows MC to sleep with other women (and you all want to play even harem)
Open path does NOT automaticially include HER sleeping with others (even she is theoretical allowed to do)
Being allowed to do does not automaticially mean that she HAS to do
Example:
You are allowed to jump out of the window of 10th floor - but will you do that?
You are able to kill someone with a knive - do you throw away all knives out of your kitchen?
You are easy killed by car accident - but you are still driving
PLEASE: start complaining when something happens - and NOT just because there is a posibility that something could happen
meaning:
Nicole probably will not automaticially sleep with others, just because she "is allowed to do"
You make the same mistake many do, whether she actually does or not sleep with others is not what matters. It is what her proposing it means for her character and how she is seen as a person.
Now she is already not helped by how she comes over as a kind of controlling person anyway and more or less is the shadow or long arm of the father as well. Her fitting with everything his choice is of the kind of life MC should lead, that obviously never really fitted with MC.
Besides what Jeff Steele already said writer loving to go close to the NTR cliffs means you already evoke many of those bad emotions for players, but it is the choice dev team made so no use complaining about that. Just decide as a player if you still want to play the game knowing they will be playing regularly at that edge and there will be likely loads of NPC centered content, shown or not.