I know that, in one of the previous iterations of this topic, I suggested a way of accommodating this need that would be technically super-simple to implement. All it would take is addition of a status-type field, like we already have for all the name, date, place, father, and mother fields. The possible values would be legally married, common-law, or unmarried partners (unless there is another possibility that I missed). The default value could be legally married.