My wife and I have been married now for fifteen years. I could not understand why she would get horny when my brother was around. Well, one night I found out. We had been drinking, and they thought I went to bed and passed out. Well, I went to go back into the TV room, and I could see into the room from the hall. I saw my wife giving my brother some oral sex. At first, I got upset. But, the more I watched, the hornier I got. Next, he was going down on her. Then, they had full sex. I went back to bedroom, and she came in after she had cleaned up. When she got in bed, I began to have sex with her, and I told her the next time she had sex with my brother I wanted to watch. Now, he comes and visits us about once a month. We take turns with her when he comes over. They said that they have been doing it for a long time now. I don't mind. It keeps us horny.