As usual, I don’t know how to properly convey it, but Qiu Shenji uses pretty formal language and makes it obvious that he’s talking to his superiors when addressing both princes.

“You’re a Prince” - it didn’t fit in the speech bubble, but technically the title used was Commandery Prince - the same rank that Li Bing used to have.

“Sixth brother” - lit. “sixth older brother”. Besides the fact that Chinese distinguishes between older and younger siblings, it is also common to specify the particular sibling by numbering them. That can even be reflected in names - Wang Qi, for example (qi there being the character for seven) is the seventh child in his family.

“Bao-er!” - “-er” is a kind of diminutive particle often used after the (sometimes shortened) name of a loved one or younger relative.

“Speak of the devil” - lit. “mention Cao Cao and there he is”, referencing the infamous figure from the Three Kingdoms period.