Miaren groans as her body is invaded, but it isn't entirely in pain.  The ointment tells her that this is a good and right thing, just as Fern's finger delving between her legs is a good and right thing.  She feels filled by the plug, and strangely - aroused.  Her anus clasps around each swelling, taking the plug deeper and locking it into her body.  The fringe of black hair brushes against her legs, seeming to sprout from her body as if it was born there.