Birthday girl's new gift is a vibrator, but it's her knees that truly get the workout. She kneels, legs spread, as she teases her wet slit with the buzzing toy. Her birthday present watches, unseen, their hand matching her rhythm. As her moans grow louder, so does their grip, until they both find their peak. The room fills with her cries and their groans, her back a canvas for their birthday gift to her.