I happened to see my sister, who is always strict with me, in the middle of masturbating. She was so engrossed in masturbating that she didn't even notice that I was nearby. When our eyes met, it seemed like things got awkward, and as a payment for keeping my mouth shut, she took out my dick and started sucking it, and stroking it between her tits. I couldn't hold back and shot a huge load of semen at my sister. My naughty secret relationships with six strict sisters, all in six chapters.