One night and two days of 1 night and left alone by my wife's sister who suddenly came over

My wife, who had a fight with her husband, has returned to her parents' house. While Koichi was spending his days alone, his sister-in-law, Nao, came to visit him. I would like to thank Nao for helping me with making up, but... Nao's true goal was Koichi's body. Taking advantage of my younger sister's absence, he repeatedly provokes me in risqués, and while he was bathing, he rinsed his back and ran into the bath. When Koichi was shown her sexy body, she refused by mouth, but Nao didn't overlook that her lower body was responding firmly...