This happened when I was staying with my sister in her house in a nice medium sized town in New York. She had invited me over so I could stay a couple of months. We hadn't seen each other in years and she really wanted to make up for the time we lost.
So, come my last paycheck I quit my job at the video store and left to go to my sisters. When I got there I thought, Holy shit! Her house was huge. It had an in ground swimming pool in the back that you could just dive into right off the back deck which was two times the size of my apartment back home. I walked to the front door and rang the bell. Nobody came to the door so I assumed she was out. I didn't hold her at fault seeing how I was three days early anyway.
I found the key taped to the rose bush beside the front deck (again bigger than my apartment) and unlocked the door. When I walked in I was greeted by a German Shepherd who was lazily dreaming away in the massive dining room.
I quietly walked to the living room where I saw the huge TV and VCR on top of it. I thought what the hell and decided to check out what she was watching. I ejected the tape and found it to be of the pornographic genre. After careful thought that lasted thirty seconds I decided to watch it.
I put it in and sat on the couch. Before I hit play I realized that there was a bikini on the couch. Obviously sis had left it out so I just chucked it into the chair and hit the play button.
She had stopped watching it not long after it was started so they were just getting into the sex. Not surprisingly it was a lesbian tape. I had known that my sis was bi-sexual since I was fifteen. I caught her in bed with one of her cheerleader friends once. Now that was a show.
On the screen the two girls were sitting in a reclining lawn chair out of doors on a huge deck. It was a fairly close shot of the one woman with nothing on sitting down facing the camera with her head back. She was moaning loudly and her hands were all over her breasts. The other woman was down on her knees eating her out. Her face was away from the camera. All you could see was her back and her perfect ass.
Now, whenever I watch a porn tape the sounds of the girls moaning and the looks on their faces gets me off more than the actual sex. Call it weird if you want, I don't care. Anyway, she was moaning deeply and pinching her nipples between her thumb and fore-finger.
I had a boner instantly. I looked around and it didn't seem that sis was going to be home anytime soon so I decided to masturbate. I took my cock out of my pants and started rubbing my hand up and down it.