probably trying to act formally towards a royalty
Well... there was a movie about that... but it was for Monday... lol.
I think he was trying to become a knight for her or something? Like act properly and stuff.
Maybe while they were travelling, they trained him
he was most likely trained to be that way towards her while he was away. she is now a princess and not known as a slave anymore while sunday/theo is still of a lower rank.
What the heck happened to Sunday!?