when a girl puts that delightful arch in her back, and sticks her ass out in a erotic/sexually suggestive manor, often accompanied by a "booty dance", that brings shear delight to the males species.
"did you see her back that ass up, playboy? it almost brought a tear to me eye, and a 2x4 to my pants!"
"did you see lucy liu bending over in the drive-thru scene in charlies angels?? ddaaaaaaaaamn, it was delightful! that the essence of female perfection!"
1. Back the fuck up. Get out of my face. Calm Down
2. Insist a female shake and rub her ass against you when dancing.
1. Damn nigga, back that ass up before I get crazy up in here.
2. Come here girl and back that ass up for me.
Get away BRING IT ON...
"nigguh you bettah back that ass up, BFore i bust a cap in yo ass"
Song that you sing to guys with big tank asses that pass your lunch table
Whoo Whoo, sweet ass Bojangles, you's a fine mothafucka won't you back that ass up