>Pie-hole is pretty stupid, as in "shut yer ~." It strikes me as equivalent to shaking one's finger in another person's face or that infantile "talk to the hand" fad. (Not sure that the word originated on the net, but that's where I saw it first used.)

Shut yer "cake hole" was pretty popular when I was growing up, mainly amongst pre-teens. I assume that this is a variation.