To get my girlfriend to loosen up, I splurged on a hot spring trip. But she brought her sister along to make sex impossible… or so I thought. Nana, her little sister, turned out to be a hidden nymphomaniac, seducing me the moment we arrived. “Playing by hand isn’t cheating, right?” Despite my guilt, I couldn’t resist her mischievous temptation. With her toned body and skilled hands, I ended up ejaculating multiple times—what a terrible, helpless mess I was…











