Because it's embarrassing, isn't it?

I have a fiancé. Like some fairy tale, he became infatuated with a young lady taken in by nobility from common birth, and he's an incredibly unfortunate fiancé who, along with multiple sons, attends to her. "...!?" She merely passes by, and exaggerates with a startled shoulder twitch, lowering her face. Seeing her like that, "You! I won't allow you to do anything to my fiancée!" He spouted such things, embracing her trembling shoulders. "He is merely a political fiancé in name. As long as I don't overstep, you may do as you please. However, excessive physical contact is troublesome. I wouldn't want some strange disease transmitted to me." "W-what are you saying!?" "Diseases can be transmitted through kissing. Of course, through acts beyond that even more so. It's common sense, isn't it?" "Don't insult my fiancée!?" It was my younger brother-in-law who shrieked hysterically. "How shameful that such a woman is my sister, even if only by marriage! Please stop this!!" "Quite right. How shameful that such a woman is my fiancée. If I could, I'd want to break off this engagement right now, so much do I find it detestable." Words spat out like poison. Well, regarding the point that this engagement should be broken off, I agree. "I see. Very well then. Farewell to you all." Now then, which one is truly "shameful"? The setting is vague. Posted on Alpha Polis.