Sure, they existed, but were they ever accepted?
What does this definition imply?
"your natural ability to make good judgments and to behave in a practical and sensible way."
On the one hand, being anti-NTR, cheating, and adultery was good judgment and thus common sense for almost all people until recently, and people still hold them as values today. On the other hand, liking those things makes you sexually deviant, but definitely not a common sensible person.
Of course they are accepted. Outside of highly religious communities and the insecure nobody gives a fuck what other people do within their relationships as long as no one is being hurt and it's all consensual.
You are arguing an entirely different point. No one mentioned anything about liking or disliking something.
The point was NTR and sharing existing alongside harem tags, which they can. That's common sense.
Whether you like something or not I couldn't give a flying squirrels left nut.
I'm not male, I don't play male protag games to self insert so i'm not the one getting cucked regardless of anything that goes on in the game. The only thing I play these games for is the story and to see hot women having sex. I just don't happen to care who they are having sex with.
I wouldn't exactly go shouting sexual deviant at partner sharing when i've seen you in incest threads.
Tell someone you are a swinger, most people aint gonna give a shit. Tell those people you are fucking your mother and wave goodbye to your social life.
Deviancy at it's finest.