@FgoSegul
the blush doesn't seem fake https://mangadex.org/chapter/1164450/14
so I think it's more like princess did find his younger self as the hero who saved her life charming -but didn't know him in depth beforehand.
now that he stopped fighting and basically does office work, he seems much more plain so her passion faded (and she didn't bother to keep in shape anymore)
But a Hero has to have many children to preserve his powerful bloodline! And a King has to have many children just in case something happens to next in line to the throne!
Thus it is perfectly normal for a Hero King to have many many wives and/or concubines! < such logic is currently screaming in Hero's mind.
Weird how you and lot of the guys here put the blame on their relationship not going well on the princess, it could just easily be on him as well. And giving how he was dumped before....
@coldb7
I'm not blaming her. Since he probably does take up too much work, it's perfectly natural for her to lose passion.
@Piyush123
yes, inomaru is a major hentai artist: you can see two of his h-manga on this site by clicking on the gear icon at the top, and selecting 'hentai' : 'view all'