Sam isn't there any information about attending a nonJW relative's wedding? There used to be I remember because people wondered about attending it in a church. I thought it was a conscience matter. My mother attended weddings and funerals of nonJW relatives, most of them in churches.
Couldn't you reason with your parents if the JWs say it's a conscience matter to do that when the teachings in that church are different, when they may believe in premarital sex and may even be marrying after they already have children then why not your situation.