息子の新婚の家に居候している、ギャンブル依存の無職の義父。そんな義父は、横柄な義娘の態度が気に入らず、毎晩息子と義娘のセックスをこっそり覗き見ていた。ある日、偶然立ち寄ったマッサージ店で、家族に内緒にして働いている義娘を見つけてしまい、二人の立場は逆転する。それ以来、義父のデカチンにハマってしまった義娘は、毎晩夫ではなく義父の部屋へ向かってしまう…
An unemployed, gambling-addicted father-in-law is staying at his son’s newlywed home. Displeased with his daughter-in-law’s arrogant attitude, he secretly spies on her and his son having sex every night. One day, while stopping by a massage parlor on a whim, he discovers his daughter-in-law working there in secret from the rest of the family, and their roles are reversed. Ever since then, hooked on her father-in-law’s massive cock, she heads to his room every night instead of her husband’s…

– JavGG.net