Surprised by my stepsister's assistance in pleasuring me while our parents were away

I was taken aback when my stepsister joined me in the bedroom, and I couldn't help but wonder what her intentions were. As I tried to shake off my surprise, my stepsister reached for my pants, her hand finding my throbbing member. I didn't know what to make of it, but I let her continue. She began to stroke me, her movements growing more vigorous as my arousal mounted. I could feel my body reacting to her touch, and I knew I was on the verge of climaxing. But I couldn't let this go on, not with our parents downstairs. I pulled away, but my stepsister was relentless. She continued to pleasure me, her skillful hands driving me to the brink once more. With a final, desperate stroke, she pushed me over the edge, and I released my hot load all over her face. It was a moment of intense pleasure, one that I wouldn't soon forget.