A father-in-law suffering from impotence looks at his wife's body and gets fully erect for the first time in six years, saying, ``It may be the last time I get erect, so please let me penetrate you just once...'' Having no choice but to allow their pussies to join together, they can't forget the taste of the incestuous dick, so they steal from their husband's eyes and spend all their time having raw sex with Serina Usui.