I can't 100% blame the MC. His sexless marriage leading to this, and it is quite strange for a monarch to not have a concubine. As the princess is kidnapped, he probably doesn't have quite the education around marriage. Quite surprised the MC can hold it for 10 years, as expected of the Japanese.
I don't know what drives the MC to sign up to this academy, and in chapter 14 it just revealed a tiny bit of it. It is just like watching Harry Potter getting into the magic school and hunted by the Voldemort army without knowing the story of his parents and his childhood hardship. Hey... it...
I love the comedy, it is so dumb and ecchi.
I see a few people looking for a story in this manga, saying things like "story had a potential" blablabla. There is a slice of life tag on this manga, you seek a story here?? lol.
Enjoy the comedy plis.