Rs' concession of differential treatment requiring justification was properly made. In the context of the present case concerning financial spousal benefits, a same-sex married couple and an opposite-sex married couple were relevantly analogous and L was treated differently to a heterosexual married man in respect of the two challenged decisions on the ground of his sexual orientation. The relationships were analogous because L and S were in a same-sex marriage valid under the law of the place where it was entered into, which had the same characteristics of publicity and exclusivity which distinguished an opposite-sex marriage