I'd say it's anti-progression at this point. One of the main reasons that he couldn't just bang any of the chicks was because it was virtually against the law but now it isn't. Hell the only reason that he had multiple girls was because they were trying to test the waters he was supposed to like marry one of them or something.
Now the monster girls are just openly dating and let alone some of them are just straight pedophiles. Yet somehow he's the only one not getting laid.
The worst part is that it was established that, for many monster cultures, one man taking many wives is normal. So, unlike many manga, this one actually has a very easy excuse to go the harem ending route. We could have resolved that plot point
ages ago. But instead of that, we get to watch the romance spin its wheels ad infinitum.
Normally, an author keeps the will-they-won't-they going to keep the audience hooked with anticipation. But here in MonMusu, this shit has been going on for so long, the romantic subplot has lost all meaning. Like, is anyone's reason for still reading this, to find out who Kimihito ends up with? Does anyone still
care who he ends up with? Once upon a time, I had opinions about who he should end up with, but I have long since lost the ability to give a shit.