Ménage à trois is a French phrase, literally a household of three. In English it means an arrangement in which three people live together and have sexual relationships with each other. The middle word is à, not et, and the first word takes an accent on the e. The phrase was being used in English by the 1850s.
What’s the origin of the phrase ‘Ménage à trois’?
This is a French term, literally a ‘household of three’, that has made its way into English. The meaning that applies to a one-off sexual liaison rather than a domestic arrangement is also known as a threesome.
The Online Etymology Dictionary dates the phrase in English publications to 1853, and records it in French twelve years before that, in 1841, as the title of an opéra comique. Its gloss names the three people involved: “a domestic arrangement or relationship consisting of a husband, a wife, and the lover of one or the other”.
An early English use in a book is Richard Burton’s First Footsteps in East Africa, published in London in 1856. Writing about Somali marriage customs, Burton says that “Old men frequently marry young girls, but then the portion is high and the ménage à trois common.” The passage is in the 1856 first edition, and Burton uses the phrase there of a household containing three people, not of a single encounter.
That is still how the dictionaries define it. The Cambridge Advanced Learner’s Dictionary gives “an arrangement in which three people live together and have sexual relationships with each other”, so the living together belongs to the definition and not only to the etymology. English has a plainer word for the act by itself, and it arrived much later: Green’s Dictionary of Slang defines threesome as “group sex involving three people of the same or mixed sexes” and dates that sense from 1969, in Sara Harris’s The Puritan Jungle.