This story is entirely true.
We are a fit couple who enjoy the outdoors, including nude beaches, with sexual play when the opportunity presents itself. She is 47, I am 52. We are professionals living in the Bay Area of Northern California.
One of our favorite beaches is north of Santa Cruz. The main beach is beautiful, but can sometimes be very windy. There is a sheltered area to the north that affords good protection on windy days. It is separated from the main beach by a rock outcropping. Normally, the sand level is high enough that it's an easy walk over the rocky area.
On this Sunday in late January we found that the northern area was nearly inaccessible. The sand level was so low that the few people brave enough to get over the rocks had to scale down the other side using a rope. It didn't look like there was much space to the north anyway and the day was calm, so we decided to spend our time on the main beach to the south.
The day was calm, but still a bit chilly. I got naked and laid down, but my wife preferred to stay clothed. She just doesn't handle the cold all that well - at least until things heat up a bit.
There were a few people on the beach. Most were clothed and no one was particularly close to us. The closest were a couple of guys down by the water and a woman who walked by on her way out.
We noticed a naked guy sitting far up the steep sandy hill behind us. It's too bad he was so far away. He probably couldn't see too much, but I'm sure he was stroking his cock while contemplating what we were up to. We would have both enjoyed seeing him shoot a nice load for us.
A clothed guy with binoculars was standing on the cliff behind us. He watched us intently the whole time we were there. He probably got in some good stroking while watching our activities.
The only other people we saw clearly were a couple fishing from the cliff far in front of us. The guy fished while the woman sat and enjoyed the view. They didn't seem to have binoculars. If they had, I'm sure she would have noticed our later activities and locked in to get real eye full toward the end of our time on the beach.