I kinda gave up on the series proper when it became clear (to me at least) that the Lamia and the Male Protag would never actually become a couple (after reading a LOT of chapters). Plus the whole 'Monster Girl Harem' gimmick wasn't going anywhere because it's not a full-on H-Manga. And since it's a comedy, any characters getting into a relationship was also pretty unlikely, because it would go against the theme of the manga.