Living together with someone is also sometimes called 'cohabitation'. A cohabiting couple is a couple that lives together in an intimate and committed relationship, who are not married to each other and not in a civil partnership. Cohabiting couples can be opposite-sex or same-sex.

This living arrangement is most commonly referred to as cohabitation. It describes a situation where two people in a romantic or intimate relationship share a residence on a long-term basis without being legally or religiously married. In some legal jurisdictions, this may be recognized as a "de facto relationship" or a "domestic partnership," which can grant the couple certain rights regarding healthcare, taxes, or inheritance, similar to those of married spouses. In the United States, some states recognize "Common Law Marriage" if the couple meets specific criteria, such as living together for a significant period and presenting themselves as a married couple to the public. Socially, the term "living together" is the most informal way to describe the status. As of 2026, cohabitation has become a primary stage in the relationship lifecycle for many couples, serving as a way to test compatibility or as a permanent alternative to traditional marriage for those who prefer more flexible legal arrangements.