"Sleeping around w/ his fiancee", someone's making up rumors to trash Seungho's reputation and maybe get his father to visit him to see the "fiancee". Chapters before we saw Seungho put a red dot on Nakyum's forehead, in their culture, that's a symbol of marriage. Seungho can try and marry Nakyum, he's a noble after all, the only thing that he has to worry about is his family.
"Sleeping around w/ his fiancee", someone's making up rumors to trash Seungho's reputation and maybe get his father to visit him to see the "fiancee". Chapters before we saw Seungho put a red dot on Nakyum's forehead, in their culture, that's a symbol of marriage. Seungho can try and marry Nakyum, he's a noble after all, the only thing that he has to worry about is his family.