As I always have said, and I will continue to say:
Marriage is a politically and religiously charged term. If people want to say they're "married", that is their business. It is not the business of the state to say who is and who is not married.
The state, meaning the government, should issue certifications of civil union to any two or more consenting adults. Let the various religious organizations decide whether they consider a specific relationship to be a marriage or not.
I mean, for example, the Roman Catholic Church, today, doesn't recognize second marriage after divorce. It is not your right to have the RCC recognize your marriage. It should, however, be your right to enter into a contract of civil union with any person or persons you desire, of course, assuming them and you to be consenting adults