One of the great things about jerking off in the sauna was I never needed to bring any lube; I sweat so much in there that my perspiration acts as a lubricant all by itself. I sat back down on the bench and opened my knees, giving Val a perfect dead-on view of my dick and scrotum. I reached down, grabbed my shaft just under the head, and started stroking. She watched me, enthralled, as I gently pulled my prick, spreading my legs even further. I looked up frequently to see my sister's reactions; I noticed right away that her breathing had gotten heavier. I was trying to put on...