You're getting ready for your date with your girlfriend. You've been sexually frustrated as you haven't gotten any from her yet and your step-sister comes in and notices. She talks to you about whats wrong and she finds out you're insecure about your cock. She has you pull it out and show her and she encourages you to stroke it a little to get it bigger. Once its big, she can't help but convince you to unload all over her chest!