I suggest we all get into ECARS.
ECARS are not the latest new-fangled electrical forms of conveyance but rather
Edenic Covenants of Abrahamic Relationship.
Edenic: ECARS predate sin and therefore predate all, every, and any form of religion. Quite obviously ECARS also predate any national laws. They also predate both monogamous and polygamous forms of marriage. (They also predate sex and children if we need to go there.)
Covenants: ECARS are lifelong agreements made between men and women in accordance with divine laws for the procreation of children (Mal 2:15). Although each ECAR is made between one man and one woman, a man can enter into a number of ECARS with different women simultaneously.
Abrahamic: This takes us straight past Adam to Abraham who established ECARS with multiple women which was a means of blessing. Christ recommended that we do the works of Abraham (John 8:39) but where is it recommended that we do the works of Adam?
Relationship: An in word that avoids saying "marriage".
Example: "Oh, we're all into ECARS here..."