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

(I did it...) Yoshinori betrayed her wife. This is because of her sister-in-law, Yu, who is right in front of me. His wife went on a two-day trip, and Yoshinori enjoyed the freedom to live alone for the first time in a while. Then, Yu suddenly comes to play. In fact, Yu had come to relieve his frustration with Yoshinori, but he had no choice but to know about this and invited him in. Yoshinori, who had given Yuu the housework, took the bath and came over...