When I started masturbating, my stepsister walked in and caught me mid-stroke. I was rock hard, and she couldn't help but stare at my massive cock. Instead of leaving, she stayed, and I took the opportunity to guide her head down to my throbbing dick. She hesitantly started licking and sucking, soon finding a rhythm that had me groaning in pleasure. Her tight lips and eager tongue brought me close to the edge, and I couldn't hold back as I erupted in her mouth, filling it with my hot cum.