The man standing in front of Alexander was one of the people with a fast brain and very good people reading skills.
And so reading the subtle clues was able to accurately guess Alexander's status, though not his exact identity.
But he did not need to do the latter.
Just the former was enough to send him into a shocked stammer.
"Ahhh! My apologies my lord…I mean sire….I mean…no..ummm…I suddenly remember I something to do."
The man was barely able to form a single coherent sentence as he shook like a leaf, and then turning to the cashier suddenly bought everything he had in his pocket and shoved it into his hand, "Here! He is my brother! This is my treat!"
And then turning to give Alexander a big smile, said "Brother! Have a good day! Sorry I could not accompany you!"
With this an instant later he was gone, trotting and even slightly breaking into a run as he tried to get away as far as possible from Alexander.