The phrase has been popularised by irish Sp'o'iral in the UK big brother #7 in reference to wannabe ghetto princess Aisleyene (sic.) and some part of her body. She does have big fakes boobs and shows her ass quite a lot, so i guess it's one or other of them. Look at the example and see what you think.
Sl'o'ice being a irish internation of slice, as in her ass is like her loaf of bread and i want a sl'o'ice. (his phrase, not mine.)