[NYH-199] Adult Mao's naughty sex education! A devilish older sister shows off her sex with her boyfriend, peels back the foreskin of her brother's erect penis in the bath, washes it, and teaches him about the female body. Mao Hamasaki (Censored)

A naughty older sister shows off her sex with her boyfriend, knowing her younger brother is watching. She comes into the bathroom where her younger brother is masturbating and starts stroking his erect penis, saying, "You have to peel the foreskin and wash it properly, right?" She then teaches his penis with her mouth, saying, "I'll give you a sex education," and makes him use toys in the room, turning on his sexual desire. Mao's masochistic nature is revealed when she gives a deep throat blowjob to her excited brother's erect penis. This time, her older sister is made to cum so much that she convulses with her brother's hard thrusts and screams.