When I met my wife, she rode quads, and she was the only woman who would go on multi-day trips to the dunes with 5 or 6 of my motorcycle/quad buddies. She was always very flirty, and she would change out of her sandy gear in front of us. There was a bit of good natured rivalry between us guys, and I rubbed it in a little when I eventually prevailed, both bedding her and wedding her.
When she learned about my cuckold fantasies, we would fantasize and pillow talk about her hooking up with one of my riding buddies or even having a gangbang. She would cum super hard during that pillow talk, and she knew that she had a green light, but she always said that some things were better left as fantasy.
She stayed flirty even after we were married, and there was always a lot of innuendo around the campfire. Sometimes the innuendo would be followed by a sudden change of subject or she would give a quick withering glance to one of my buddies. I would get a little insecure, and I would probe her for whether she had any secrets or confessions. She knew I loved the fantasy of confessions, and she would make up an elaborate confession about whatever I had been probing. Sometimes she would heap on unrelated confessions, like having fucked one of the guys the night before our wedding. Her stories got us worked up for years, and there were some months where every time we had sex (and we have a LOT of sex), she would tell stories.
On the last trip to the dunes, only four of us went, and she stayed home. I was riding my KTM-450 motocross bike, and all the other guys were on quads. All day, I was kind of showing the other guys up, and rubbing it in a little that they had softened up enough that they couldn't ride bikes any more. By the end of the day, we had all had about a case of beer each, and we were sitting around the fire. We were all pitching Trent ******* about having sold his bike to buy a side-by-side quad. He had gotten a little soft around the belly, and he got sensitive when I said something about a side-by-side being a glorified golf cart for guys too fat to ride bikes or quads. He looked right at me and said that at least he still had a big dick, and he wouldn't need a side-by-side if he didn't get a sore back from fucking my wife so hard. Everyone started looking around at each other, and I could not tell if it was because he had crossed a line in his joke, or whether everyone knew something. He immediately passed it off as a joke, and everyone jumped in with jokes and moved the conversation along.
We stayed up listening to music, and started smoking pot. Eventually, we were all pretty mellow, and I was feeling kind of paranoid, and I wanted to check in with my wife. The only person with cell reception was the guy with the side-by-side, and he had been texting all night while we partied. I asked if I could text my wife, and he said sure, and he tossed me the phone. I started typing in my wife's number, and it auto-populated. I texted "hey sweetie" to my wife and hit send. I started typing in that Trent had loaned me his phone, and she replied before I did, saying "don't you mean hey sexy?" I laughed and asked how she knew it was me. My curiosity was going now and I started scrolling back on the thread. her next text came in, saying that of course she knew, the number was in her contacts. I scrolled back quickly now, and saw a picture looking down a big belly to a huge dick, to my wife's pretty and cum covered face. As I was sitting there shocked, a text came in from our missing buddy Kevin. It was a close-up of a hairy gaping pussy with cum running out of it, and past the open pussy, I could again see my wife's pretty face! And she was laying on the new sheets she was putting on the bed as I left.
By the end of the night, I learned that every one of my buddies had fucked her, separately and in groups, and that they were all getting a big laugh about having been able to keep a secret of it for so long. I was less humiliated by her fucking other guys than the fact that they all were sharing a secret, and she had told them all that it was because my cock was so small!