I guess most importantly its really the old folks' opinions. My friends advised me that ask your parents and in laws first. if they are ok then fine. if not then don't go or invite anyone just married or getting married. She told me she has a friend who didn't believe and went to attend a wedding that time. Now, many years later, her son has leukemia and the mother in law took this reason and blame her... even so many years later. Plus keukemia can be due to many reasons ma right? But just use this and blame her lor..
So..I guess to avoid such things, better not to go against the old folks in case it became a never-ending issue.
But I am not sure how.. if you dont tell them and go do it la.. haha