As I feel a shiver run through her body, I trail a finger around the rim of her vagina, penetrating her slightly, before moving the tip down over the nub of her clitoris, rolling the ball over the hard, glistening surface, trapping it between my finger and her pubic bone beneath.  Releasing her clitoris, I draw my finger back over her vagina, and up to circle, teasingly over the rosebud of her anus before continuing the deep, probing massage of the muscles in her buttocks, ensuring that each deep, outward stroke of my hands separates and spreads her cheeks, while the down and in strokes compresses and squeezes them back together.