1. See remove notion that the reply which I am going to place here for public consumption may constitute "dual certificate" reply. One certificate has to be sacrificed and with another registration future will rule in case any matters goes to court. Also note that both of you should agree to it first and simply saying "my parents sentiments" needed to be pleased hence I may follow your reply may also not solve issue in hand. I belief in that both partners in marriage has to agree to something first then pleasing parents sentiments comes.
2. Having said above here is i-gyan;
See what has happened currently is that you changed your religion, adopted Christianity and than married according to Christian rites and ceremonies. Thus both of your Christian marriage is not only solemnized under the Indian Christian Marriage Act,1872 but from there pops a Valid Marriage Certificate issued by the Priest as per authority given to them to issue such Certificates. However, a copy of the same is sent to the Registrar of Birth, Death & Marriages to be recorded under as Indian Christian Marriage Act,1872. That ends the statistics part so far Govt. is concerned.
3. Now the social tricky part with which you came to us can also be solved provided first you two should agree as well as your wife's parents should agree to it then below is remedy with backdrop on how it goes about;
Under S. 15 of Special marriage act, 1954 one can get any form of religious marriage (Christian Marriage in this case) Registered for which proof of marriage (photographs, wedding card, marriage certificate of the religious priest or from a temple as the case may be), age of both parties (21 years for boy and 18 years for girl), proof of address (for the purpose of jurisdiction of the Registrar of Marriages in the District where Registration of the marriage sought), 3 adult witnesses with their I.D. proof is all that is required. compile all above and take assistance of a young Advocate and go to nearest Registrar Office and place particulars and the registrar office issues one month notice which has to be followed in Special Marriage Act Registration. Caste / religion is not mentioned in Registration of Special Marriage Act.
The moment you act on above, the Notice goes to both families for formalities purposes (I mean for objection or their no-objection) and then the Marriage get Registered after one month notice expires and if no objection received by the Registrar of Marriages under the special Marriage Act. Here in my opinion generic parents are not that smart to fish out papers submitted to find out what Ceremony their apple of eye went earlier with to object or get a shocker of their life as you say (my parents should not know about change of religion etc...)!
4. Now, the earlier religious marriage after getting Registered under the Special Marriage Act, 1954 will be covered under this Act only for all purposes and will be considered as civil marriage from the date of Registration meaning thereby a Christian marriage after the Registration under the Special Marriage Act,1954 will not remain religious marriage but will be "civil marriage" under the Act. The Christian Marriage Act, 1872 will not apply in the marriage and in case of any dispute amongst the parties the adjudication takes place under the Special Marriage Act,1954 only.
By above your change of religion will be hidden from your parents + your parents will feel joy (till in future someone tells them) that my son did not change his religion to get married and your immediate problem also gets solved.
But, I wonder why you being an adult male did not consult an Advocate before as marriage is a important decision a adult takes in h/er life! This observation besides the point now take this reply to a young advocate and ask him to help you with running around and paper work and act accordingly at District office of registrar of Marriages under whose Jurisdiction where your Registration falls unto to get on such Registration done with.
Also note general people should not shy away seeking in-chamber discussions with Advocates in their day-to-life for their problems, we are only their to present remedy and average advocate(s) donot dent pockets J
