ethical slut
n.— «She might, for instance, describe herself as an “ethical slut.” That is the title of the polyamory “bible” published by two Californians, Dossie Easton and Catherine List in the early 1990s.» —“The Language of Love for Polyamorists” by John von Radowitz Scotsman (Glasgow, Scotland) Apr. 3, 2005. (source: Double-Tongued Dictionary)