A ménage à trois (French: [menaʒ a tʁwɑ]) is a French term used to describe a situation where three people are involved in a relationship and live together. Each of the three has a sexual relationship to the two others. A form of polyamory, arrangements are sometimes identified as a throuple, thruple, or triad.
In 2021, the first ever throuple couple got married, and it is now officially legal.