When I went back home for my wife's birth, all of her sisters were dressed defenselessly, so it was only natural that I could see their breasts and panties, and I got a full erection! Since I haven't had sex since my wife got pregnant, I got a painful erection. Of course, I was found out, and when I tried to hide it in a hurry, my wife's sister said, "You've been pent up, haven't you?" and secretly jerked me off when my wife wasn't looking... This isn't cheating! I told myself, and took advantage of my sisters' kindness and ejaculated over and over again! To be honest, young girls are the best.