Was Greece the birthplace of humanity?

[Thryleon]

There's a relatively simple way to keep things above board.

If there is little truth in the comment then odds are this comment stems from a place that is just taking the pi55 and is hurtful.

Examples. 

water being a Jewish cocktail (yep derogatory,  not true potentially mean spirited stems from historical class division).

Someone being fat, thin, red haired et Al.  Statement of fact.  Context might make comments about them mean spirited,  but the comments are descriptive.

Call someone a fat bastard who eats all the pies, mean spirited even if true. 

It really isn't hard.  before saying anything ask if there is anything mean spirited about the joke.  If there is, then odds are it shouldn't be said.