I am 68, retired and love sex. I am fortunate that my wife is 10 years younger than me and enjoys sex. I am well endowed, with a thick 8 inch erection and I have plenty of staying power. I can sometimes fuck my wife for half an hour, bringing her off 2 or 3 times before I come. Last week I took my dog for his daily walk over the local park. It was very quiet as it had been raining and more rain expected. The park has pathways with open grass areas and is surrounded by woods. I was halfway into the park when a young girl about 20yrs old was walking towards me with her small dog. As she approached I saw she was about 5 foot 6 and had a nice figure. She had a tight fitting black short jogging top on. This showed off her large bust and erect nipples, obviously no bra on. She had tight black Lycra jogging pants covering her shapely legs and black trainers. As we passed we said good morning to each other. I carried on walking my dog. About 20 minutes later I saw her again across the other side of a grass field without her dog. This time she was with a man. They were walking towards a wooded area at the end of the field. They then walked into the woods. It was now raining quite hard so I changed my route and walked quickly over where I last saw them. I put my dog on his lead and we followed the path into the woods. I walked quite a way into the woods and as I approached a bend in the path I saw the couple ahead of me. I slowly walked on and stopped by a clump of bushes. There I saw that she had taken her top off and the bloke was sucking one tit and had his hand down her jogging pants. They were about 4 foot off the path. I moved back and tied my dog to a small tree. I got back behind the bush and watched. She was undoing his trousers and pulled them and his pants down exposing his erect prick. She then got on her knees and gave him a blow job. He then took his shirt off. She stood up and they both stripped naked. She resumed sucking his prick as he held her head. They then moved slightly and I had to move to see them. She was now sitting on a fallen tree with her legs spread. He got on his knees and got between her legs and was licking her pussy. After about 5 minutes she came with a moan. He stood up and she got up and turned around with her hands on the tree and spread her legs. He then started to fuck her from behind. As he went in and out of her big tits were bouncing all over the place. My prick was rock hard in my trousers. I decided to get my dog and walk past them to get a better view. As I drew level with them I stopped and looked at them. They both saw me and continued fucking. I tied my dog up and approached them. I stood about 3 foot from them, they continued fucking. I got my prick out and wanked as I watched them. The male then asked if I wanted to have some fun. I told him yes. The girl told me to strip off and join them. I wasted no time and stripped off. He was still fucking her, so I got the other side of the fallen tree and offered her my prick. She took it into her mouth and sucked me. She went up and down my prick. The bloke pulled out and told me to knell behind her and lick her pussy. I got down and licked her moist shaven pussy and arse hole. He then gave me a condom and said I could fuck her. I rolled it on and entered her warm moist cunt. He told as I was about to come pull out, remove the condom and come in her mouth. I fucked her for 5 minutes and felt I was about to come. I pulled out whipped off the condom and she turned, got on her knees. She opened her mouth and both the bloke and I stood in front of her wanking our pricks. We both came in spurts into her mouth. We all sat on the tree naked talking for a good half hour, not worrying if anybody came along and saw us. I found out Dave and Clare like to have risqué sex in the open and be caught by strangers, who they don’t mind joining in. We arranged to meet the next week, but not to bring our dogs and see how many people we can get to watch us having another threesome. I might see if the wife wants to join as we have never had sex with other people and she might be up for it as she does love a good fucking.