One day, while traveling to a hot spring with relatives, my cousin—who used to worry about her massive breasts—showed off her now fully grown, voluptuous figure. While we were all bathing together, my cock naturally got hard, and seeing this, my cousin grew visibly flustered. Pretending to wash, she grabbed her huge tits tightly in her hands. When we were finally alone together in the outdoor bath, our excitement rose, and as we touched each other, she took my cock into her mouth in the bath and later on the washing area. Taking advantage of the privacy, we secretly had sex. It became a moment where we naturally shared our overflowing emotions together.