Duke Dean Hildayden’s wife, Berlia, had a crush on her brother-in-law—Cain Hildayden—since before she got married. Under one roof, Berlia lives under the same surname as Cain, but as his sister-in-law. She has lived her life trying to erase Cain from her mind. But one day, Berlia witnessed her husband, Dean, having an affair with another woman. After witnessing her husband’s affair, Berlia felt a sense of disappointment in her marriage. At the same time, while her husband is away from the mansion, Cain comes to visit her room…… “……maybe you heard it wrong. It’s late, so……go back, Cain.” She told him to go back as if nothing had happened. It would be uncomfortable the next time she met him, but she needed to resolve the situation like this. If she told him to go back like this, he would have no choice but to do so. Rather than that, no matter how much he heard a moan, was it normal for him to come into his sister-in-law’s room and secretly watch her masturbate? She was confused. And then, unbelievable words came out of Cain’s mouth. “I don’t think I heard it wrong. Weren’t you excited, sister-in-law, no, Berlia?” “What……” She couldn’t deny it. Because everything he said was true. Cain approached Berlia who was unable to answer, and whispered, “Did you expect someone to stroke you like this?” Cain stroked Berlia’s cheek and spoke with a seductive smile, “How about this. During the three months without my brother, I will spend the night with you?”