We were partying on new years. We were all dressed up. At the of the night we were staying at my SIL place. My wife and I were getting ready to go to bed I had unzipped my wife's dress. As she was crawling into bed, she was bent over. My SIL came in and asked me to unzip her dress. Her ass looked so round and hot. I fucked my wife really hard to orgasm thinking about them both bent over on the bed and taking turns on both of them.