It was a hot, sweaty summer day. My sister Mia and I were spending the day at home without our parents. The air conditioner was broken, and the muggy heat in the room made her skin damp and clammy, wearing loose clothing that exposed her chest. I couldn't resist Mia's innocent temptation to show off her breasts and beg for attention, and we had our first sex while soaking wet with sweat and bodily fluids. In the bath, in the hallway, in the kitchen, we gave each other blow jobs and fingered each other, and had perverted sex while covered in sweat. I blamed it all on the heat and kept poking her little ass over and over again... A summer memory with my sister.