Celestia, the regal alicorn from Equestria, finds herself in a forbidden liaison with a human, her curiosity piqued by the differences between their species. She agrees to let him explore her tight, uncharted equine ass, a first for the princess. He lubes up her tail and hole, gently easing his thick cock into her, stretching her virgin anus. Celestia moans, her horn glowing as she's filled in a way she's never experienced. The human grips her hips, pounding her relentlessly, his balls slapping against her pussy. Celestia's tail swishes with each thrust, her pleasure mounting as she's taken like a filly in heat.