As I was leaving for college, my stepsister slipped and fell onto my lap, her plump ass smashing against my crotch. She gasped, clearly feeling my hard-on through our layers of clothes. I tried to ignore the arousing sensation, but when she remained there, her weight grinding against me, I couldn't help myself. We made eye contact and without thinking, I unzipped my pants and freed my erection. She looked down with curiosity, then back up at me with a mix of fear and intrigue. She tentatively reached out and touched it, her soft fingers wrapping around its girth. Before I knew it, she was stroking it skillfully, causing me to moan softly. Suddenly, she took it into her mouth, her warm throat enveloping the head as she began bobbing her head up and down. Her actions were turning into something far beyond her control.
