‘Kaafir mat bano’ is just an alternate to ‘behave’.
I remember Sindhi ladies referring to their children as ‘Kafir / Kafiryani’ for their mischievous attitude.
Probably, this is not limited to masses, but Sufi poets who otherwise chant:
na main momin wich maseetan,
Na mein vich kufr dee reetaan
Na mein paakaan vich paleetaan
Na mein Moosa na Firaon
Bulleya ki janan mein kaun
comes with lines:
Jo zar mango tu ba zar hoon.
Jo sar mango tu hazer hoon.**
Mukh moroon tu kafir hoon**
So this term ‘kaafir’ has very negative connotations in our society.
On other hand term ‘Momin’ is also used to refer meek and subtle people like the term ‘Allah lok’ , ‘sain lok’, ‘sufi mansh’ are used.
Question is, whether this is only with Muslim families where we use Kafir and Momin in this way? Do non-Muslims of our society refer their naughty / mischievous children as Muslims or like terms?