Outdoor sex in California
We were at a hot springs resort, where we could camp nude and soak nude. It was a pitch dark night. We were in a hot spring pool with other people nearby as we stroked each other. Not having the nerve to have sex within a couple of feet of others, we got out and went to a cedar-lined hot tub nearby with a view of a field under the stars, where we fucked furiously, with the possibility of someone else coming at any moment.
Another time, we were at a different hot spring in the daytime, with one pool about 10 feet lower than the others. Everyone was nude - two young female yoga instructors were in the pool with us; we conversed with them as I had my back to a boulder and my wife was backed up to me with my hands on her boobs under the water and stroking her pussy. The young ladies decided to climb up the rocks above us to join some other people; as soon as they were out of sight, I lifted my wife up and lowered her onto my cock and began to fuck her furiously as we could hear the other talking and laughing maybe 20 feet away; they could have peeked over the top of the rocks at any time (and for all I knew, they did). It was hot, and I'm getting stiff again just telling about it.