I suggest talking to your parents about it. If they like the idea, then by all means go right ahead. If however they wish to spend their anniversary doing something other than sitting in a hot church or tent or gazebo or some other location, crammed full of people, for several hours, while a priest or minister reads possibly the most boring thing I've ever heard in my life, just to have the hosts run outside into a car and drive away, then don't do it man.