These men are domestic partners.
The definition of a domestic partner refers to someone other than a husband or wife with whom you are in a committed, serious and usually permanent relationship.
An example of a domestic partner is a man or woman's homosexual life partner.
either partner () of an unmarried heterosexual or homosexual couple in a relationship (domestic partnership) considered as being equivalent to marriage for the purpose of extending certain legal rights and employment benefits
A person other than a spouse with whom one lives and is romantically involved.