Each working person has the opportunity to designate someone who takes on a supporting role, and I'd think this person would have to live at the same address to count.

I have a friend who's primary residence is in Tennessee, yet his job and secondary residence is in Virginia. He only sees his wife once a month, and spends most of his time at the secondary residence. I know this is like comparing apples to oranges, but what about the instances where the couple doesn't live together?