JJs are purely at the discretion of the organiser - GNAS does not have a rule about this (despite what some judges try to maintain). At Adel we accept married/civil married/recognised cohabiting, both sexes/single sex. After all, our prize is usually a bottle of port, so not something that many would feel the need to bend the interpretations for.
It is possible, however, that a trophy has been donated specifically for (say) "same sex cohabitees who have been together less than three weeks". In which case, that is the definition of JJ at that tournament.