You know what, I think I understand
Why So Serious Bruh? and what he's explaining.
That cheating wife scene in the story technically IS NTR since that scene is the definition of
Netorare/NTR - Japanese term for a character that is not the MC, cheating or being unfaithful to the MC. Used in hentai media.
Meanwhile, Netori/NTR(Also shortened as NTR) - Japanese term for a character that is the MC, cheating or being unfaithful. The MC is the one doing the stealing of LIs. Used in hentai media.
They describe that having the "NTR Switch" Off let's it so you don't see "NETORARE Scenes" in general. NTR ON - Show the scene in exact detail. NTR OFF - Have the MC explain the premise without showing the scene.
I think that's what's happening here? Good job Detective Zeruel, pat yourself on the back.
On a side note, I think this is how F95 defines NTR in their tags:
NTR Tag - Netorare
Cheating Tag - Netori