The harem is super ok... But if you plan to add NTR/Sharing I would like to know that in advance before committing to this game...because I don't like NTR.
The harem route isn't a 'serious' one at the moment, it's more like a fun bonus content thing, I will give it some attention in the future and see if I can make it work with the story (no promises!). The story is mostly finished and NTR/Cheating is not part of it, if I were to add something like that, it would be half-baked and conflict with parts of the story itself, plus it would change the entire relationship dynamic.