NHDTB-449 My sister, who remembers the clitoris's position, is curled up in her futon masturbating... I can't take it...

My little sister sleeping next to me is secretly playing with herself in the middle of the night! I was messing around with her out of curiosity, and she said 'somehow, it feels really good...'. The futon writhing lewdly, the sound of her panting... I can't sleep now!!! Unable to hold back, I sneak in and make her feel sticky and wet! Eventually, we cross the forbidden line and have incestuous sex! She learns to cum hard while being pounded by big brother's dick!!