When the labia minora(inide lips of vagina) hang out like a penis, but when you touch it, it will invert itself like when you touch the eye of a snail.
When an elderly woman has such a plump, round, juicy, fat ass that she cannot perform basic actions with her lower body without producing a loud, ear piericing clapping sound.
"Me and your Nan's juicy, Flappy Clappy made sweet children last night." I say to you