beta
...The rating is quite low but it's honestly not that bad? The ML isn't abusive or has personality issues, she lives quite well and is quite capable, and the pacing is decent. They have good chemistry and retort too. She's not proactive but not a total doormat, and he knows that, which is why he's trying to help her live a more confident and fulfilling life because it's in her best interest. Chapter 16 really dumps a lot of background work for why he chose her as duchess and how he sees her.
While the ML likes teasing her, he probably won't do anything to her since it's a really tame Japanese shoujo publisher. They have an age gap, but that's quite normal for a historical (especially since it's not an isekai). For that era, she's the prime age for marriage, not only because mortality rates were much higher back in the days but men of the upper class married late because they had to focus on their careers (versus commoners who work and marry closer in age).