1
general::
Cohabit, especially when not married. For example, "I . . . am only concerned that their living together before the marriage took place should be so generally known" (Jane Austen, Pride and Prejudice, 1813). [c. 1800] Also see LIVE IN SIN.
American Heritage Idioms
2
general::
Phrase(s): live together
1. [for two people] to dwell in the same place. • I live together with my sister in the house my parents left us. • Henry and Jill live together in their parents’ house. 2. [for two people] to dwell together in a romantic relationship. • I heard that Sally and Sam are living together. • They are living together and may get married.
McGrawhill's American Idioms And Phrasal Verbs