@yekku_I have not been on that situation, but I suggest either you buy some more time to think about it with a cool head or call the wedding off. Knowing that you are not comfortable and still committing for a life long relationship is probably the worst mistake you will ever make in your life. Remember two lives are at stake. As far as you not feeling comfortable goes, I have nothing for or against it as we all have our own beliefs and values. After all, you will be the one who will be spending the rest of your life with that significant other and I certainly do not recommend you change your opinion or feeling based on what others say at this thread. Do what you feel is right for you, do what is more likely to make you comfortable, and do what you think will enable you to do things on your part to make that relationship work.