Recently, Tsukasa has been increasingly dissatisfied with her intimate life with her husband and finds herself masturbating more often alone. One day, she accidentally catches sight of her son-in-law Atsushi secretly masturbating at night... His overwhelming huge dick captivates her heart instantly, and she decides to offer him sexual relief instead of her uncooperative daughter. Throughout the day, Tsukasa sneaks opportunities to pleasure herself with Atsushi's massive cock, milking him dry again and again like a thirsty slut. As he continues to get fucked senseless, Atsushi becomes unable to think about anything but his aching balls... Note that the contents may vary depending on the distribution method.