Maybe I think that is when the MC gets off on it. MC here doesn't get off on it he just doesn't care. Though to be fair it's just as disgusting as netorase and makes this unreadable garbage.
Everything is consensual, there's no cheating, just pre-approved sex, for example, the Succubus acts like a proper Succubus, they seduce and drain their prey with sex to manipulate and/or kill them. This dungeon story is hardcore and not for someone with a weak stomach.
The narration was worded awkwardly. Also what's the point of dominating someone who is not only already submissive to you, but submissive to everyone?
Focusing on acquiring women while aspiring to be a king or ruler makes me wonder why even aim so high? In a medieval era anyone with land and a title could have multiple wives. It's like working your ass off to join a Fortune 500 company when all you want is to eat at a $15 buffet.