Mine came from my husband. He is a fire chief which means we go to a fair amount of award ceremonies, holiday parties, swearing in ceremonies,etc.
Well,he isn't very good with the social stuff. So when I started going to these events with him and we met his friends ( who call him "Bones"), he would say somethiing like, " This is my wife," and walk away. So the guys just started calling me Mrs. Bones.
It stuck.