One time we were having a picnic at our house and I went into my house to get some more beer. I looked into the kitchen just in time to see my brother grab my wife's ass. I was shocked when I saw my wife did nothing to stop him but instead she just let him continue to grope her ass! They didn't see me and I watched my brother manhandling my wife's ass. I snuck back out side and realized I had a raging hard on. I kept an eye on those two the rest of the time and noticed at one point they both disappeared together. I snuck into my house through the back door and notice my bedroom door mostly closed. When I peaked in, I saw my brother's naked ass, his pants around his ankles. I could only see my wife's legs but it was obvious she was on her knees in front of my brother. I watched my brother's naked ass pumping back and forth and I heard my wife's slurping and gagging sounds as my brother fucked her in the mouth. I was transfixed on this scene and didn't even realize I had pulled my dick out and was stroking it. I continued to watch my brother's naked ass pump back and forth until finally his ass cheek tightened and he started grunting! I knew he was now shooting his cum into my wife's mouth. I shot my load at the same time! I had to try to clean up my cum as my brother pulled his cock out of my wife's mouth and pulled his pants back up. He never said a word to my wife. Just tucked his big cock into his pants and walked out leaving my wife kneeling on our bedroom floor, her hair a mess from being used as a handle and wiping his cum off of her just fucked married mouth!!!!