Does someone knows if the story of the game changes if I stay in a monogamous relationship with only one of the characters? Like, only getting hearts with just one character and rejecting others "invites"?
Some events only happen if you have a high enough relationship with one of the characters. Like, I don't think you can do the Bareshade expansions unless you have a good enough relationship with Bernard to be able to talk to him about it at his home at night.
I don't think so tbh. Maybe some dialogue changes but other than that, I don't think there is any meaningful difference. Would be stupid if we had to create a different save for every single character in such a big game