You have to be truthful and input your correct marital status on your application for naturalization: "married". Otherwise you risk having your application denied based on "fraud" and or "lack of good moral character."
Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
Make an appointment with an immigration lawyer and the lawyer will explain what to do. There is not enough infornation posted here for me to tell what your question is, or what you need to know.
If you are married, you are married and that it what you need to disclose.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.