My wife and I are trying to decide if we should support and/or attend the wedding of my brother-in-law (her brother). He is divorced and will be remarrying in a Protestant ceremony. Both he and his fiance are Protestant and were never Catholic. He and his former wife were baptized, therefore that marriage is technically indissoluble unless it was invalid. However, I have reason to believe the former marriage was invalid.
We want to be able to support his new marriage because we believe the former one was invalid. Is our belief in the invalidity sufficient reason to support it, or should we take the position that the former marriage is valid until he gets a Catholic annulment? I have no reason to believe he would be willing to seek out a Catholic annulment of that marriage at this time. (He has no reason for him to believe that the Catholic Church has jurisdiction over his previous marriage).
We do not want to cause scandal, nor do we want to counsel him to remarry if it is indeed a sin for him to do so.