Looking for a very particular type of story.

First off, I am amazed on how quickly some people here come back with responses to very vague descriptions. Its actually quite impressive. Hopefully I have as much luck. Im looking for a story to share with my wife. I have been trying to talk my wife into having sex with another man while I sit quietly to the side and watch. No humiliation, no participation on my part. I want her to carry on with this other guy like I'm not even there. Then afterwards I would reclaim her. Im looking to find a story that encapsulates that set up. Something descriptive and sensual and most certainly, HOT! Of course it would be best if the husband was lacking in the "marital equipment" department and the bull was more than equipped. Anything anyone can recommend would be greatly appreciated. Thank you.