As she stretched and flexed her tight young body, the scent of her arousal filled the room. Her breasts bounced enticingly with each movement, barely contained within her sports bra. I couldn't resist any longer - I stepped closer, my hard cock throbbing with desire.
My step-sister was unaware of my presence as she continued to work out, focusing intently on the mirror in front of her. I took advantage of the moment by reaching out and undoing her bra, freeing her perfect breasts from captivity.
Her eyes widened in shock as she caught sight of me, but that didn't stop her from continuing her routine. She gasped as my fingers found their way to her erect nipples, teasing them gently. With one swift movement, I positioned myself behind her and thrust my hips forward, pushing my cock against her ass cheeks, ready to penetrate her tight hole in the next moment.
