My name is Onoue Koji. I married Wakaba three years ago and we are a happy couple. My younger sister and her husband moved into the neighborhood six months ago and have been coming to visit us often. My younger sister has always been a free-spirited girl, and the other day I found out that my brother-in-law has a pretty big dick. Anyway, I thought that our relationship as a couple and as a family was going well, but the other day I saw my wife and my sister's husband embracing each other.