It was a hot summer in the early 1950’s. With both parents working, my twenty year old sister Mary and I were out of school on summer break. Mary is two years my senior. With no air-conditioning, each afternoon we would seek relief from the heat by talking or reading as we laid on the cool sheets of her bed.
One day, which is etched in my memory forever, as we prepared to do the usual Mary began to take off her blouse and lower her shorts. She was standing there in her thin panties and see through bra. This was such a shock to me as I had spent hours spying to see her naked or at least in some state of undress and here she was! As she disrobed she looked at me and nodded. I assumed she wanted me to follow suite. I stared at the dark triangle of brown hair showing through her thin white panties and the top of her pink areola and erect nipples pressing against the thin top half of her bra.
Pulling down my shorts and tossing my tee shirt to the floor I stood in my white jockey shorts. Turning from her I tried to push my now stiff cock up against my belly. Mary laid down on her stomach and I lay next to her on my back, not daring to move for what seemed like an eternity. I glanced down at her beautifully shaped butt and with a trembling hand, began to lightly stroke and rub her ass cheeks. I was cretin she would make me stop. To my surprise she didn't resist. Was she asleep? Then I heard,
“HmMmmmm...Uhmm.,.” As she ground her crotch into the bed.
