So, in David Copperfield (98% sure that’s the right book) there’s this annoying character that always makes a point of calling David ”Master Copperfield.” Now as Americans we assumed that he was be mockingly subservient, but our Prof explained that in Britain (at least at that time) Master is a title only applied to children. Once Copperfield was of age, he should have been addressed as Mister Copperfield.
Bearing that in mind please consider that Alfred still refers to Bruce Wayne as ”Master Bruce.”