It was sort of like a blog about this man's wife. The wife has gone to a costume or halloween party in another state and the husband doesn't go with her. But he decides to go without telling her and dresses up for it. He gets to the party, not recognized, and see's that a lot of the women are dressed really slutty, including his own wife. Eventually he ends up watching his drunk wife, who is roughly around her late thirties, give a blowjob and eventually have sex with a bunch of guys. He also ends up having sex with a few other women. It ends I believe with him watching her have three guys, then a young guy, then the young guys dad, all fuck her one after another, eventually with him not telling her that he had been at the party. I can't find it anymore and idk how else to find it. Good luck and thank you.
Source: reddit.com/r/sexystories/comments/2ffs80/im_looking_for_a_story_that_was_on_here_about_a