Ménage à trois
What's the meaning of the phrase 'Ménage à trois'?
A living arrangement comprising three people (not all of the same sex) in a sexual relationship. Alternatively, a sexual liaison between such a group of people.
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.
See also - other French phrases in English.