Walk at the lake

Last week I decided to go for a walk around the local lake at 7am in the morning as I have each day for the past three years. The lake is about two miles to walk around and I normally walk around it twice each day. Most days there are old and young couples walking, young guys jogging and occasionally some nice young woman to look at.
On this occasion there was a very fit looking couple of about 20 to 25 jogging around the lake of whom I had not seen before. They jogged past me heading in the opposite direction. The man was about 6 foot tall, very muscular and was wearing a singlet, jogging shorts and sports shoes. The lady was around five foot six inches, looked very fit, was wearing a yellow singlet, white shorts and sports shoes. She had brown hair in a ponytail, nice set of breasts and a suntan to match.
At the time I thought she was very attractive but after they jogged past I didn’t think of them again.
After I had finished my first lap I went and sat down on a seat just near were I started walking to have a drink of water.
I had been sitting there for about five minutes when I could here what sounded like groans from behind the bushes near where my car was parked. At first I thought it was a dog barking or children playing, so I decided to go and check in case someone was in trouble.
I walked then crawled through the bush for about ten yards until I came to small opening. There about five yards from me was the young joggers I had seen earlier. The lady was laying on the ground with her boyfriend giving her the best oral licking she could have received. He was licking as quickly and firmly as possible and she was enjoying every bit of it and was groaning quite loudly as she bagan to orgasn. This was obviously what I had heard earlier. Both of them had no clothes on and the man was swinging in the wind with his massive manhood. It wasn’t long before he was planting this huge dick into this very wanting young lady.
I had started to feel my shorts getting bigger and before long was rock hard with my seven inches wanting to get some action of its own.
The man pumped into this lady for all he could in the missionary position for about ten minutes. He then withdrew and turned her over then entered her from behind and once again started to give her all he could. She was now about to orgasm again and the moaning began to get even louder than before. The stamina shown by this man was unbelievable as he kept on thrusting time and time again into this enthusiastic young lady. All of a sudden his body just started to spasm as he began to ejaculate laod after load into her. She was moaning so load as she had yet another orgasm. Finally he withdrew and the last remains of sperm landed on her back before they collapsed in each others arms.
My shorts were damp at the front from pre cum and I still had a very hard dick as I turned around and crawled back through the bush to do my second lap.