You sneak into your step-sister's room to rub yourself while worshiping her feet. She's aware you're there, but lets you think for a couple of minutes that you've been stealthy. To your surprise, when she catches you she isn't upset. In fact, she's quite playful, even encouraging you to take your dick out and stroke it. Step-sis takes it to another level and takes out her tits, then commands you to cum on her soles. It seems she really loves knowing your weakness and hints at using it to her advantage in the future. She gives you her socks as a gift to remember this moment.