My older sister, who still treats me like a child, interferes with my studies and private life. She even barges in while I'm taking a bath and sees my foreskin penis, then says, 'You have to wash it properly!' and pulls back the foreskin to wash it! My penis can't help but get erect! Seeing this, my sister excitedly moves her hand, and I cum from the intense pleasure. I thought this was bad, but my aroused sister says, 'Hey... shall we do something more adult...' with a super erotic face that I've never seen before…
