Same-Sex Common Law Marriage in Iowa

My fiancee and I would like to officially become a common law couple, but we want to be sure that the steps we take actually affect our marital status for taxes, insurance, and so on. We tried to talk to our local courthouse about any requirements or applications that needed to be filled out and they told us that that information would constitute legal advice that they therefore could not give. To my understanding, all we need to do to qualify as a common law couple is to identify ourselves as such and to behave as such. We already share a bank account, vehicle title, credit card, apartment, and have a pet together. We plan to exchange rings in the near future. Our questions basically are: -Do we need to take any official steps (i.e., fill out an application) to formalize a common law marriage? -Does Iowa common law apply to same-sex couples as it would to opposite-sex couples? -Can we, as a same-sex common law couple in Iowa, fill joint state and federal taxes?