Returning home from the dormitory, I was aroused by the inadvertent glimpses of my four sisters' mini-skirt panty lines, whom I hadn't seen in a long time. My sisters noticed my slightly matured erection and, in a more provocative manner, tempted me further. Unable to resist after my sister grasped my penis, I was secretly allowed incestuous sex, culminating in a competition among all of us to grab my erect penis!
