Ryona is not LI of MC - no NTR no sharing. simply make Ryona with her son falls into incestuous relationships and "that's all, folks!".
I don't see much point in Rayona's existence in the story - well, she whined about how hard it is for her with her son, that he doesn't listen. and that's all. and if you load her with hot incest content - it would be a completely different story =)
yes, true, she invited MC to visit for dinner, but... but! MC yet have LI - it's his daughter, if my memory serves me right. if you don't try to be a cheater, then personally I immediately said goodbye to Linda (who bullied MC's daughter at school).
well, you can go visit Rayona, in order to discuss things in a more private setting, where MC can refuse pursuit her personally as LI (close LI path) in favor of (open Ryona alternative Incest path) turning her into a hot sugar mommy who gives sugar to her own son. (mini-happyend of Ryona story - like in "Forbidden Passion" mini-story of incest what MC read in his smartphone) as you see no NTR and no sharing.
other women and girls - there is nothing serious with them.
if you somehow manage to send Goldie to hell, then there will be pastoral peace and quiet and grace.
although, if the game had a BDSM part, where Goldie may be trained as a sub, like Bella, older sister of MC from "sisterly lust" - then that would still be okay, Goldie is a sub-sex doll, I would like that hehe =) because sub is not relation, sub is sub - some sort of "friend" on eternal basis, sex toy. not an obstackle on the way of official girlfriend.