New home purchase slipt between two people who are not married.?

My 'husband' and I are not legally married but are considered common law. We just purchased a new home in September and I am starting to receive all of the tax doents for house. I am not sure if our state (Oklahoma) recognizes common law marriage so I don't know if we'll be able to file jointly. If we are required to file single who is suppose to claim the house or do we split it?