My wife has, should say 'had', an aunt & uncle in North Carolina who called themselves 'mother & father' in front of their children and ...
well everybody.
Both me and my wife looked at each other the first time it occurred, as if to say,
WTF is that all about?
Creepy indeed.
Joking around I told her she should call me 'father' too. She replied,
I will leave you yesterday.