We don't. But the issue for me is not threesomes, foursomes or moresomes but that Naomi had the power to turn the MC from a relatively nice guy into a dishonourable weakling, who broke a solemn promise he made previously to someone close to him that he loves.
In a nutshell my point is this: Naomi has the power to influence people enough to make them act out of character, for her own gratification, on a whim.
She's a selfish and a bad girl sure enough even though I rank as one of my personal top three ToN women.
In real life girls like that ruin lives and are as destructive as nuclear weapons.
(I speak from experience.)