The daughter and son-in-law wanted to save money to buy a house, so they went to live at their mother-in-law's house. Previously, Maiko used to work as a photo model, and she had no idea that her son-in-law was a fan of hers. One day, Maiko accidentally discovered her son-in-law watching a sex movie with actors. very similar to her, surrounded by photos when she was a model. He used her photos to masturbate his son-in-law's huge cock, making Reiko unable to take her eyes off. It turned out that because the cock was so big, it caused Maiko's daughter pain. It had been a long time since her son-in-law had had sex, so he had to "deal with it" alone. Feeling sorry for her son-in-law, Reiko decided to offer her daughter to "take care" of his big cock. At Maiko's invitation, combined with having endured it for so long, he couldn't resist anymore. From then on, the two continued to secretly fuck each other every chance they had, secretly maintaining this wrong relationship...