OK, this is a really interesting story and I like the characters, too, but it got ruined for me due to a certain incident in one chapter and I tried to carry on after that but my frustration just wouldn't die down...
So, the male lead is a Duke and the female lead is set to be his wife, and one day the empire's Princess comes to visit. The female lead makes a slip up during their interaction, and the princess lets the Duke know she's going to punish her and asks if he will have a problem with that. He says no, she can do as she likes, and then just stands there while the princess slaps his fiance really hard across the face.
Now, I detest face slaps against women in manga and webcomics. Sometimes, the context makes it OK to read on, and at others it's a deal breaker. Anyway, in this context you can understand that maybe the Duke was powerless against the whims of the Princess and had no choice but to stand by and let it happen. But afterwards he makes no attempt to apologise to the female lead, or even express his regret that it happened. She was physically assaulted, and it isn't even mentioned. He doesn't even look at her face and ask if it hurts.
Um, sorry, no. You can't just turn the page on something like that. And you especially can't start being mega affectionate and clingy as if she has earned your trust by taking a slap from the princess or something. Come off it.
Male leads can come with all kinds of faults, but the type I can't get on board with are the 'face slaps are fine' kind, whether they are the ones doing the face slapping or just watching it happen.