In our shared home gym, my blonde, fit step-sister, unaware of my presence, begins her yoga routine. Her tight yoga pants accentuate her plump ass and camel-toe, making me stiffen. She bends, stretches, and grinds against imaginary cocks, her pussy lips visible through the thin fabric. I can't help but stroke my throbbing cock, fantasizing about her smooth, tight pussy. She notices me, playfully teasing, "You like what you see, big brother?" She rubs her pussy against my cock, making me cum in her panties, leaving a wet spot that she proudly shows off.