Marrying without her father’s knowledge
Question

                I am looking at a lengthy engagement period
      before my fiance and I am able to financially marry and live together. We would both like
      to have a nikkah during our engagement so that we are not sinning when we are intimate
      with each other. However, both of our parents are against this and want us to wait until
      our marriage reception which is in a year or so. Is it allowed for us to get a nikkah in
      secret? My second question is, is it ok for us to repeat the nikkah ceremony again during
      our reception (since our parents won't know of our first nikkah)? Is a double nikkah
      permissible to the same person? Your help is much appreciated.
Praise be to Allah.You will find a detailed answer to your first question under 
  Question #2127. Know also that you can never have 
  a proper marriage contract without your fathers knowledge and consent. 
  Indeed, he or a person designated by him must marry you to the man who has asked 
  for your hand. Once the marriage contract has been made according to Islamic 
  law, meeting all the required conditions, then there is nothing wrong with having 
  more than one waleemah (wedding reception) in more than one place. And Allaah 
  is the source of help.