Deciding to push her even further, I slid my index finger away from her front, moving it down past her perineum until the tip was resting right against her tight, puckered asshole. Without asking for permission, I applied a firm, steady pressure, easing the first knuckle straight into her tight entrance.
Penelope's entire body went completely rigid. She let out a high-pitched, muffled shriek, her toes curling into the carpet as her inner muscles clamped down around my finger with an unbelievable, vice-like squeeze. The sudden, intense invasion completely broke her dancing rhythm, her hips freezing in place as she trembled against me.
"Evan… fuck! What are you doing back there?!" she yelled, though she didn't try to pull away. Instead, her head dropped onto the back cushion of the couch, her face flushed a deep, violent crimson as she looked up at the ceiling.
