Old story request

Does anyone recall an old story from about ten years ago where the author watched his wife fuck another man in the refreshment booth at a softball field? For the life of me I can't recall the title. His wife was takes and horny and there was a substitute player on the husband's team. The substitute player was a surfer hunk from California who flirted shamelessly with the wife, until they consumated in the closed refreshment stand. The husband crept in and observed from the shadow.
Great story!