Mom and dad are out for the evening and left me in charge because I'm the oldest. I check on you to find out that you were trying to jerk off! I notice you are having trouble so i over some encouragement, after all, I'm your big sister and I only want whats best for you baby bro. I finish with a count down game just like when we were kids and encourage you to spy on me in the shower while i clean your cum off of me.