I had just graduated from high school. Turned 18 just before school had ended. I'm 5'6", around 210, dark brown hair, hazel eyes. Name is Bob. My sister is 19, 5'2", 110, blonde hair and blue eyes. Nice firm tits and sweet ass. Name is Sue. We were both living at home.
Her friend Kim would come over quite often. She was a lot like my sister body wise. She was about the same height and weight. She had auburn hair and green eyes. I'm a sucker for green eyes. I would do my best to be around her as much as possible.
We had a pool and at least 2 or 3 times a week they would go swimming. Both wearing very small bikinis that barely covered anything. My bedroom window overlooked the pool and I would sit in a chair at the window and watch them. Especially Kim.
One day my parents were gone for several hours. As I sat and watched my sister took off her bikini and went in nude. Holy shit. She was better than I had thought. But when Kim did the same and joined her, I almost filled my shorts. She had the most beautiful puffy nipples I had ever seen. Up to this point I had only seen them in pictures and movies I watched on my laptop.
As I sat there watching I got the shock of my life. My sister swam over to where Kim was sitting on the edge of the pool. She kissed Kim square on the lips than moved down and sucked on those beautiful puffy nipples. I had to shake my head to see if I was imagining it if things cleared up and changed. Nope. Sue was still between Kim's legs but had since moved down and was licking Kim's pussy. I could see because Kim had laid back and was squirming like crazy.
I immediately pulled off my shorts and took my hard cock in my hand. I was stroking furiously and watching Sue eat Kim. I could tell Kim was close to cumming. She raised up and grabbed Sue's head and held it tight against her pussy. I knew she was cumming and so did I. I shot rope after rope of cum all over the window.
I continued to watch as my sister got up on the edge of the pool. Kim got in the pool and proceeded to return the favor to my sister. She licked and sucked at my sister's pussy until Sue sprayed all over her face. I than shot my second load all over the window.
I remember yelling, "Oh Fuck" the second time. It must have been loud enough that they could hear me through the glass. They both looked up but I had ducked down before they had a chance to really see me. So I thought.
I cleaned the window off of the evidence of my spying session. Got my shorts back on and went downstairs to the kitchen. About 10 minutes later they both came in.
"Hi Bob," Kim said. "How are you."
"I'm fine, thank you." "You"?
"Doing great thanks," Kim replied.
I got a little grin on my face as I knew why. I watched every move she made. The way her tits would wiggle when she walked. How her ass cheeks would move up and down with each step. Lucky I had already blown two loads or I would have had to cover up.
This went on for several months. Kim would come over and on days our parents were away for a few hours, or at work, they would eat each other at the pool. And I would coat my window. And I would watch Kim's every move. What I hadn't noticed was how Sue was taking it all in. How much I was watching Kim.
One day my parents were at work but Kim had not come over. I was in my room laying on the bed watching T.V. Wearing a t-shirt and a pair of shorts. There was a knock on my door and my sister asked if she could come in.
"Yes. Come in," I told her.
She opened the door and came in closing the door behind her.
"Bob," "Can I ask you something"?
"You can ask anything you want sis," I replied.
"You always watch Kim's every move when she is here." "But you never really look at me." "Am I not pretty"? asked Sue.
"You're beautiful sis." "And you have a great body."
"I know how you know that." "I know you have been watching Kim and I at the pool."
"Shit." I'm sorry." "I didn't know you saw me." "Damn sis, I'm really sorry."
