Secretly pleasuring myself and ejaculating on my adorable stepsister's rear while she sleeps

As I unwound from a grueling day at work, I found myself irresistibly drawn to my stepsister's enticing derriere. I couldn't resist the allure of her youthful, voluptuous form, and my desire grew uncontrollably. I surreptitiously undressed, my hand exploring my pulsating manhood. I dared to reach out and caress her sweet posterior, my excitement escalating as I felt the softness of her skin against my throbbing member. My hand slipped down to her tight rear entrance, and with a desperate thrust, I penetrated her. The thrill of the forbidden and the ecstasy of the moment sent waves of pleasure coursing through my body, culminating in a powerful release that coated her lovely rear with my warm, sticky essence. The audacity of my act left me breathless, yet the satisfaction was undeniable. This was a secret only I could know, a tantalizing taboo that I savored every moment of.