A son feels something is off about his stepmother Mari who came to his house after his father remarried. One night, he peeks into their nighttime activities and finds a big penis between her legs! His young and beautiful stepmother is a tomboy! Confronted with her secret, Mari has no choice but to do as her stepson tells her. She serves a stranger and has reverse anal sex, and then engages in incestuous anal sex with her stepson, stroking herself until she ejaculates explosively! Even though she is obedient, her stepmother Momo Mari cannot resist the pleasure and ejaculates repeatedly.