Vax: I’ve been really angry at you
Percy: I’ve been encouraging it
Vax: I don’t know if it’s entirely fair, but I can’t shake it. I don’t know that I’m willing to let go of it yet
Percy: Good. I certainly do not deserve it yet. I don’t know if I ever will.

Ha, Vex realising that she owes fealty to Percy and calling him ‘my lord’ and him laughing and telling her not to

Also Percy telling Vex the best thing about a title is realising how much you don’t need it, and assuring her that this doesn’t have to change anything