Pygophilia
pygophilia : A paraphilia involving sexual attraction to the human buttocks.
Callipygian
cal·li·pyg·i·an ˌkaləˈpijēən/ : Having well-shaped buttocks.
Steatopygia
ste·at·o·py·gi·a/ : accumulation of large amounts of fat on the buttocks, especially as a normal condition in the Khoikhoi and other peoples of arid parts of southern Africa.
Skinny - Scrawny - No Ass - White Chick - Meaning...
Me! :)