Huh, now that you mention it, there is some twisted logic going on there. "Stop being considerate! You need to be more considerate about how being considerate affects other people!" Not even trying to find a compromise or anything. She just seems outright manipulative to me.
Yeah, it's always a bit annoying when LN/manga want to have it both ways with being harems or proper monogamous romances. It would be more fun if Jeanne and Tekka could actually have their own things going on besides repeatedly trying and failing to vie for the attention of a guy who's committed...
I'm genuinely surprised you guys are so critical of the storyline. I don't mean that disrespectfully either-- I'm usually the kind of guy who does that in spades, but I've never really thought of this manga as much more than an excuse for Nonco to draw cute/funny romcom shenanigans and softcore...
Author definitely only even did that for the sake of having a dramatic twist-- no other character development-focused motive. Much like the rest of the social tension in this arc, I expect it will dissapate into nothingness and never be meaningfully brought up again.