Looking for a Story

[phatjack]

If i am not mistaken it was about a guy with his wife on a camping trip with his boss who cancelled and instead the boss's son took his place. There was a voyeur scene with the guy and the boss's son watching his wife getting fucked by a different guy through binoculars on an overlook. The last thing i remember is that he told his wife to pretend to be the wife of the guy that was fucking her. Hope this is the correct information and i didn't blend stories together. I've tried searching through Lit and through google advanced search. If you know the story i'm looking for thanks in advance!