It was a sunny afternoon midweek and I was walking through the conservation area close to our house. I was in a wooden area, mature trees surrounded me on all side. I noticed the birds had stopped singing and I could hear a dull moaning sound coming from up ahead. Quietly I made my way towards the mysterious noise. They were up against a tree, some thirty feet ahead, a young couple. She was a cute blonde and her boyfriend was a husky guy. The girl had one of her feet up on a lower tree branch and the guy was driving his cock in and out of her, hence the moaning. She had her skirt hiked up around her ass giving me an excellent view of his cock ravishing her cunt. I was mesmerized, and got hard immediately. My hand went down into the front of my jeans to grab my dick while I watched from the cover of the bushes. I tried to wank quietly, so they wouldn't hear me. I shot my load in my jeans before they had finished, so I got out of there as quick as I could.