My wife and I have been married for a while but I still haven't met her sister Mayuki. This time Mayuki had a day off so she came to our house to visit. This was also the first time I met her. At first sight, I was fascinated by her beautiful F-Cup breasts. And it looks like she's not even wearing a bra! Her nipples seemed to want to escape from the tight shirt, the top half of her breasts were clearly visible to my eyes thanks to the off-the-shoulder shirt she was wearing! Mayuki's seductive actions quickly made my cock harden. And when we couldn't take it anymore, we continued to secretly fuck even when our wives were nearby! I'm really turned on by this illicit relationship. And I wanted to repeat those exhilarating, stimulating experiences with her. We fucked each other while visiting my wife's parents' house, I even fucked her right next to my sleeping wife!!!