Hey step-bro, do you mind going to the store and grabbing some milk for me? It’s cold out and I don’t want to get changed. You insist on seeing what’s underneath my robe, surprised to find your shy step-sister in lacy lingerie. You tell her if she gives you jerk off instructions, you’ll go to the store for her. Don’t want to miss Saturday morning cartoons right? She’s really shy, but you can tell deep down she’s a freak. She starts instructing you, making you blow one huge milky mess.