I just learnd a little bit of korean from teacher (like some basic grammer, and like 50-100 word), and I think they have like 3 level honorifics (? or more?) like when you speak with your close family, speak with some random person from your class, or speak with the bigboss. And as I saw from the raws, I find the honorifics in his speak (I didn't undestand what they say, but honorifics are easy to find, if you know what to search for), but when he said he look like a pushover, I don't think he used them. And there was no difference in the "Duke", I think it was purely what the ML said before, and how he looked at the trashy father. (and how he used his voice)