@SleepyAbra no it's literally from the gossipy cousin seeing her buy the cufflinks. In the novel in this scene everyone is wondering why there has been no man wearing blue cufflinks in high society, hence why those masked noblewomen presume he must not be noble in this scene. You buy cufflinks for your lover or family and the duke hasn't been seen wearing them yet either.
Her dad doesn't want her to marry the prince at all lmao. He immediately asked Max's name to be removed from the list. He says the dude doesn't meet the qualifications because he utterly adores his daughter and thinks no man could be good enough for her. He probably interpreted it to mean his lineage/ability wasn't good enough for the duke. I expect in the future we'll see him treat Mikhail with the same disdain now FL shows no interest in him (probably lucky if he doesn't get run through with a sword seeing as the duke thinks he made her cry lol).