This happened right after we were married and living in an apartment complex in Florida. We had the unit 2 doors down from the laundry room. It was a hot, muggy evening when my wife decided to put a load of laundry on. She went and came back a little later all flustered. I asked her was was up and she explained that a guy in the laundry was hitting on her pretty aggressively. I looked at what she was wearing and laughed. She had on a very skimpy tank top that showed off her assets in a very nice way, including being semi-transparent so her nipples were showing. It turned us both on so much that some guy was lusting after her that we made sweet love and had simultaneous orgasms. Our fantasy has always been since then to show her off to other guys but never go through with it. The tease is enough of a turn on.
Source: reddit.com/r/gonewildstories/comments/7e4bpo/mf_man_comes_on_to_my_wife