Mostly non-fiction story.
My woman led a diverse and active sex life starting at a youngish age. I get highly aroused when, on occasion, she relates some of these adventures. The story below happened when the summer after her sophomore year at University in Tennesse a few months after her 19th birthday.
Go back about 25 years.
Steve and Sue had decided, on the spur of the moment, to hitchhike to the Blue Ridge Mtns and find a trail to hike for a couple days. All they had with them were backpacks with a sleeping bag. Stupidly, they only had a couple cans of food and some bread, and some good grass. They did have a small canteen.
Steve and Sue were mainly just friends at school and had never really "dated". Sue had a couple regulars as dating material during the year.
After they arrived at a logical jumping off point for the trail, they started the hike. It was about an hour or two into the hike that they ran into 2 other kindred couples. They were better equipped for overnight camping so it made sense to join forces with them.
By early afternoon is was hot. In the past hour they had only one other group.
"Let's all strip and hike nude in the hot weather" declared one of the other guys. The only shy one in the group was Steve. He didn't want to be the odd man out, so joined the crowd and, like the others, was only left with his hiking boots on.
As they continued their hike, Sue noticed that the boys would get erections at various times. Also, a few times, one or the other of the couples would disappear off the trail for 10 or 15 minutes at a time. When they reappeared, it was fairly obvious the couple who reappeared had been doing more than exploring nature.
They only ran into two other groups of people before they arrived at their destination - an informal camp site adjacent to a small lake. Sue had heard one of those people thay passed mutter something about those "blankety-blank hippies".
There was no one else near their spot at the lake. It was still daylight so they all went skinny dipping before lighting a camp fire. Since Steve and Sue didn't have a tent, they placed their sleeping bags on the ground about 25 yards from their new friends tent.
As the sun went down the girls simply put on T shirts. The boys did put shorts on. Sue had assumed that was to cover/protect their respective penises (penii?) that all had been in some state of engorgement most of the day. The only exception, as Sue had noticed, was when they were in the cool lake water.