My parents remarried and formed a new family. My stepsister and I went on a family trip to a hot spring and ended up mixed bathing! My stepsister came to mixed bathing with me to get closer to me, but her huge, explosive breasts were too big to hide, and her nipples were completely visible when they fell out! As I was getting aroused, other guests came in, and my stepsister hid behind me, causing her huge breasts to press against me, revealing my erection and causing me to get extremely excited! My stepsister also got excited by my penis... She secretly used my fingers in the water to climax repeatedly! Of course, that wasn't enough, so we ended up having sex until the end!
