Ok so here's the situation: My finace has a half sister (his mom had her when she was very young, and apprently there has been alot of issues and tension between them throughout the years). My Fiance would like to have his sister attend our wedding, but now his mom is saying that if she is invited, she wont come!!! WTH! What are we to do in this situation!? We are pretty freaked out because we did not anticipate NOT inviting his sister. How do we get them to set their differences aside for ONE day so we can have the wedding of our dreams?