My wedding will be a Catholic Mass, and one of my readers at the mass will be my 17 year-old cousin. He will turn 18 1 month before the wedding, but will not be 18 yet when invitations are sent out for the rehearsal dinner. Do I need to also invite my aunt and uncle (his parents)? If I invite his parents I am also concerned that I will then need to invite other aunts and uncles who technically are not involved in the wedding ceremony. What is the etiquette for this situation?? Any help is appreciated. Thanks!