Derives from the impossibility of reassuring a person with insufficiently pleasing buttocks
A: Girl, no jeans in the WORLD gonna help THAT flat ass!
This insult should be used carefully if the intended target is within earshot and of African descent as you will probably become the victim of a violent assault. Directing this insult at a Caucasoid female is a lot less dangerous as it may be taken as a compliment.
Other noted recivers of this insult are:
i)Skinny girls. Ususally wearing very big or string type belts in the hope of creating a feminine figure
ii)White guys. Who reputedly all have a flat ass, even the fat ones.
iii)Black guys. Displaying the opposite of the Arsenio Hall afliction
Friend 1 turns to his buddy and observes "look at that flat assed hoochie mamma trying to shake what she doesn't have"