I went for an early morning jog due to the fact it was going to get extremely hot in the afternoon. It must have been around 5:00am when left my house and the weather was already somewhat hot. I was sweating profusely and decided to take a break at the halfway point which I usually do. It was coming up to 6:00am now and I was right by a lake. I didn't see anyone around and figured I would take a quick dip to cool off. I took all my clothes off and went in for a few minutes. It was very refreshing. I came back out and put my clothes back on and continued to sit around when about 10 minutes later three women, who look like they were in their late 50's, come by. One of them tells me I shouldn't masturbate in public like I did. I told her I didn't, which was the truth, and she said the three of them saw me. I once again told them I didn't. The three of them told me they knew I didn't but now expected me to. I told them I wasn't going to. One of them says she thinks they can change my mind. She tells me they saw me in the water naked and took a few pictures. She said if I masturbate for them that they will do nothing but if I don't do as they ask they will show the police my naked pictures and tell them that they saw me masturbating and want me arrested. One of them was holding a cellphones up now and smiling. I told them I wasn't going to do it. Another one of them made a comment asking me who the police would believe, me or the three of them with naked pictures of me. She made a good point and I was worried about getting charged with doing something I hadn't done. I agreed to do as they asked but only under the condition they delete my naked pictures and not call the police. They agreed but only after I did it. I undressed and there I was naked in front of the three of them as they watched me cum for them. It took a lot longer than usual for me to cum as I was extremely embarrassed doing what I was doing in front of them as I had never done something this with anyone watching. I think they enjoyed it was taking longer because they were getting to see a younger naked guy stroke himself longer. Finally I did cum for them and they were pleased. I asked for them to erase the pictures now and they asked what pictures. It turns out they didn't have any naked pictures of me and that only one of them thought they had seen me naked and they decided to use that against me. The fact I gave in to them made them realize I must have been naked. As they were leaving they said it was nice to see young cock but that I was such a sucker for exposing myself so easily. They said I could have so easily got them to strip before I did what I did so all of us would have been naked. They then added with all of us naked you never know what could have happened.