Anatomy Lesson With Stepsister

You're cramming for anatomy and Willow—your stepsister—shows up with exactly the kind of hands-on study aid you need. First the tits. She peels her top off and you get familiar with the skin around her nipples, tracing every ridge, giving each one a pinch that makes them stiffen quick. She lets you cup the whole soft weight while you map out the fat and the ducts underneath. Then it’s south. She kicks her shorts off and spreads for you, guiding two of your fingers right onto her clit. You study the swollen little nub in earnest—press, circle, watch the slick spill out when you get the pressure right. She’s breathing hard, hips twitching, clearly getting off on being your personal reference manual. Test day comes and you ace it. Willow keeps her word. She locks the bedroom door, drops the robe, and says it’s time to start your practice on her for real. You play doctor first: grab her tits again for a thorough exam, listening to her breath hitch while you squeeze them like you’re checking for lumps. Then you pop the thermometer between her lips, between her legs, wherever you want—her laugh turning dirty as you check every hole you studied. She flips the script, pulls on a cheap nurse hat, wraps her fist around your cock and tells you it’s her turn to test the equipment. She strokes you stiff in two seconds, checks the pulse at the head with her tongue, then climbs on. “Time for the insertion test,” she grins, lines you up and sinks straight down until you’re buried balls-deep in that warm, wet cunt she let you map earlier. Her hips start rolling like she’s taking your temperature the old-fashioned way and neither of you cares about staying quiet anymore.