Three people, a couple and the wife's younger brother, live together. - The wife had a physical relationship not only with her husband, but also with her brother, who was officially recognized by her husband. - A close look at the unusual daily life of husband and wife having sex at night, and having sex with a sister and brother after her husband goes to work. - The three of them know that they are having sex separately, but according to an unspoken rule, they never watch. - After getting each consent, I show off my sister and brother having sex in front of my husband...