The daughter and son-in-law wanted to save money to buy a house, so they came to live at their mother-in-law's house. Maiko used to be a photo model, and she didn't know that her son-in-law was a fan of hers.
One day, Maiko accidentally discovered that her son-in-law was watching a movie with an actor who looked very much like her, surrounded by photos from when she was a model.
He used her photo to masturbate his son-in-law's big cock so that Reiko couldn't take her eyes off.
It turned out that because the cock was too big, it hurt Maiko's daughter, and it had been a long time since her son-in-law had had sex, so he had to "solve" it alone. Feeling sorry for her son-in-law, Reiko decided to offer to "take care" of this big cock on his daughter's behalf. Before Maiko's invitation, plus the fact that he had to endure it for so long that he couldn't resist it anymore. Since then, the two have continuously secretly fucked each other every time they have the opportunity, secretly maintaining this wrong relationship...
