With a mischievous heart, I hid under the bed to surprise my sister... Naked, masturbating, having sex with her boyfriend, and seeing my sister's usual unseen appearance right in front of me! Thinking about the erotic things happening right above my head, I got so hard that I couldn't get out! With my rock-hard dick, I peeked and got caught by my sister! Thinking I would be scolded, my sister got excited seeing my erect dick, and I was pushed down on the bed, leading to a forbidden incestuous relationship!