cohabit

US /koʊˈhæb.ɪt/
UK /koʊˈhæb.ɪt/
1.

sống chung

If two people, especially a man and woman who are not married, cohabit, they live together and have a sexual relationship:

:
About 23 percent of men and women aged 25 to 34 told researchers they had previously cohabited with a partner without it leading to marriage.