I just remembered another one, from when we played kingmaker. One of our DMs didn't like the Imperious bloodline's written explanation (descendant of various rulers) so I explained it as being descended from various Sorcerer rulers.
This evolved when my character referred in Character to his cousin, a lawyer. This was a reference to another campaign we had played where I had played an Infernal bloodline tiefling, who was LN and tried to be a Contract Devil.
This progressed even further when a high level Sorcerer showed up in the campaign, and was explained to be one of my cousins, who I later played as to give him some backstory in a chronologically earlier campaign.
Back to topic, I have had a couple half orc cavalier characters who chose Order of the Dragon, which I refluffed to "Order of the Bro." The Order of the Bro often act like a group of Frat boys and we almost got into some PvP when my character wanted to help out his fellow Bros before helping out another PCs sister and mother, on the grounds of "Bros before Hos."