Voyeuristic experience with a horny granddaughter's underwear

In a thrilling turn of events, I found myself in an exhilarating situation. I had infiltrated the bedroom of a stunning granddaughter, with the intention of spying on her private moments. To my surprise, I discovered her indulging in self-pleasure, wearing nothing but a pair of underwear. The sight of her bare skin and the allure of her body was too much to resist. In a moment of uncontrollable desire, I succumbed to my urges and began to pleasure myself, all while keeping an eye on her. The thrill of the forbidden made the experience even more intense, as I fantasized about what it would be like to be with her. The sight of her underwear, the only barrier between us, only fueled my lust. I found myself lost in the throes of passion, my hand moving faster as I imagined what it would be like to be inside her. The sight of her underwear-clad body and the sound of her moans still echoed in my mind, making me wish for more.