My sister got divorced 2 years ago and she became more close to me and my wife. We started to hang out more, none of us have kids so life is complete freedom. A few months my wife told my sister we are swingers, she didn't know but become interested so we decided to make her initialization to group sex at home and only us. It started with a simple massages between us and I had the pleasure to get my cock sucked by my sister for the first time and finger her pussy what was a real turn on.