Jack was home alone most weekdays. His wife Jill was an overworked and over-stressed junior executive for a design firm, and traveled widely. They loved each other and had good sex when they could; but that was becoming less and less often as Jill climbed the corporate ladder. Jack was, in temperament, the opposite of his wife. As a freelance technical writer, he did most of his work at home and only traveled on vacation with his wife, and a few times a year to writer's conferences. He had total control over his schedule, and most weekdays he could make some time to relax and enjoy life.
Jack masturbated as much as the next guy, he supposed; but as time went on and sex became less frequent, he found himself doing it a bit more (he supposed) than most 30-year-old men. When Jill was away, he brought himself to climax at least once a day, often twice. When she was home, he would have preferred to have intercourse every day. Jill was an extraordinary woman: 5'7," short blonde hair, athletically trim and sexually explosive, when she had the energy. The problem was that she seldom had the energy after a week or so of jetting across country from New York to Los Angeles to Dallas to San Francisco. By late Friday night of such a week, she was pretty much dead to the world at least until lunchtime on Sunday, when Jack might hope for a quick lay before she struck out for the airport again.
His usual routine was to write for a few hours in the morning, then he would drive to a nearby wilderness trail area and go running for an hour or so. He was in pretty good shape for someone with a sedentary job, and he paid attention to his body. He was 5'9" and weighed about 145. Though losing a little of his wavy brown hair, he kept his boyish good looks to a great extent.
Something about running made him horny. He didn't really know why; it was a fact that endorphins and testosterone were both increased by exercise, and they combined to give him a post-exercise erection most days. He usually took care of it by stroking off vigorously in the bedroom before taking his shower; but as time went on, and he missed Jill more and more (and missed sex more and more) his mind began to wander to thoughts of lust while he was still running.
One particular day, it was warm and wet in the forest, and Jack ran as usual. He ran every day, rain or shine, as most devoted runners do. He liked getting wet when the weather was hot; it kept him cool. This day he parked at the trailhead and got out of his little station wagon. Where usually there were several other cars parked nearby, there were none that day because of the weather.
Jack pulled off his sweats and tossed them in the back seat, then went for his usual run. It was just drizzling when he left, but about a half-hour into it, the rain fell harder, and Jack got really soaked. His running singlet and shorts were a silky fabric like nylon, and when they got wet, they clung to him. His nipples and penis were subject to a pleasant warm friction, and his erection began to come to life while he was still about ten minutes from his car. By the time he got there, he had a raging hard-on.
He got into his car, and began to pull on his sweats over his shorts and shirt, but they were so wet that he decided to strip them off in the car before getting back into his sweats again. He had a brief thought for the local indecent exposure statutes and what they might imply in a public car park; but there were still no other cars there, and with the rain and the window-fog in the car, there was little chance of someone seeing.
Jack pulled off his shirt, the wet fabric rubbing lasciviously across his erect nipples. Without really thinking about it, he flicked his fingers across the two stiffening tips, and his penis grew harder. He kicked off his running shoes and hooked his thumbs in the waistband of his shorts, and slowly pulled them down. His penis sprang free, and after removing his shorts, he was entirely naked in the car.
Hoo, boy, thought Jack, I'm going to come right here in the car if I'm not careful. But then he thought, why wait? He was alone in the car with no other cars around and little chance of a pedestrian or a cop happening by in the streaming rain. He could see the only entrance and exit to the trailhead about 100 yards away; behind him, there was impenetrable oak and pine forest. But though there was only a small chance of being observed, the fact that there was any chance at all began to appeal to him. Suppose someone did see him? Suppose he got caught? As he thought this, a generous globule of pre-come emerged as if on cue from his rock-hard penis.