Usui is just messing with sensei at this point, power plays everywhere. Too bad it's at the cost of Souta's autonomy; he's hardly a character anymore, just a humanoid dildo that replies to conversation.
Wasn't as much of an issue when it was just Rikka, Souta actually had some input back then. This'll be getting a DNF/10 from me.
Just had a look at the raws...it's eh. While the threesome was predictable as hell, it feels shallow as hell. Souta isn't even a character anymore, what's the point of being in his POV? It's always "this person is this, is it the curse? Who am I in love with?" It's not even indecision anymore, the author is just dragging it out. Ch.25 introducing another demon, and another character is a death sentence. Basically just Nisekoi with foreplay.