So remember this, if you decide you are married and file a return using married filing jointly, you aren't just married on this tax return. You are married forever in the eyes of the state of Texas and therefore everywhere else. You must file every subsequent tax return as married and do everything else for the rest of your life (unless you get a divorce) as if you are married -- credit card applications, mortgage, buying a car, etc. Once done it is very difficult to un-do, so take it seriously.
Financially, you are probably better still calling yourselves unmarried (fiancee, etc) especially if one has low enough income for EIC but combined you don't.
