In that thread, the OP wrote:
I wanted to ask couples about their experiences with keeping outside involvements limited only to "sex (f**k) buddies" or "friends with benefits" status only, and not allowing these interactions to progress to relationships (bf/gf, romantic, etc).
Are there any couples out there that maintain these boundaries? What have your experiences been and how did you go about setting up your own set of rules/guidelines?
The above gave me the impression that the OP was negotiating with a partner and this option was one of the things being discussed. So, I assumed the OP was coming here for research and support, to see if such an arrangement was workable or considered reasonable, and to be informed before resuming the negotiations. Of course, we won't know what motivated creating that thread unless the OP comes here and explains, but I did not see it as outside the purview of this site.