Because same-sex marriage is legal, the IRS will not recognize 2 unmarried people as "married" for income taxes. Therefore, each partner must file a separate, single return (or possibly head of household if you provide care in your home for a qualifying dependent) with the IRS.
However, the state of California does recognize RDPs and allows them to file a joint state return. Therefore, you must file separately for the federal government and together for the state.
Usually, that means that partner #1 prepares a separate federal return (single or HOH) and discards the state portion. Partner #2 does the same thing. Then both partners prepare a joint federal return and a joint state return (because Turbotax can't prepare a joint state return unless you first prepare a joint federal return). But here, you discard the joint federal return and only file the joint state return.
