I think this comes down to not knowing which chars are affected, so not risking it at all. You might not care about sharing most of them, but don't like the idea with the 1-2 that you have a deeper connection. Also never considered ntr might be with other females, guess it depends on the game.Apparently most of the players (which, no need to say, are mostly males) wish that the male MC is the only one who has sex with all the female characters. Sharing is caring, but only when 22+ females share the MC wich in turn is not willing to share his girls with other males and sometimes not even with other girls.
Plain patriarchal double standard.
Also still waiting on full vo before starting s2