SonicWizard is right.
This author always does that with his novels endings, ALL of them.
It's his trait at this point, dude makes interesting stories and characters but shets the bed with the endings.
I liked the novel since MC and his girl were cute and their relationship advanced... but then the author decided to add harem starting with the priest girl and I lost my interest.
First time I hated the harem introduction into a story.
I stopped reading any Ecchi - borderline hentai type of manga because I know authors will turn like this
Also same, I even started reading MTL novels, KR and CH ones, besides a few things I dropped almost all JP stuff
I was thinking something bad would happen in the story but it's just the usual shenanigans of this kind of story, like harem, lazy mc, randoms gushing over him, 7 deadly sins....
The most offputing thing tho, maybe? the novel has the incest tag too