The underlying source of Double Standards
that make some jokes okay, and some jokes that, are essentially the same, as bigotry and a Berserk Button
to the people targeted.
This is why its okay for kids to hurt adults in slapstick humor but not the other way around. And why minorities can complain about the White Establishment but when reversed it reads as racism. Why a poor man can complain about the rich, but when the rich complain about the poor its insensitive. And why Double Standard: Abuse, Female on Male
Typically whoever holds the more power in general societal class terms can't make fun of someone with lesser social standing because it becomes abuse of power. This applies to age, sex, race, and even religion in some cases.