P
Paganus
Guest
Assuming you have already spoken with your sister, all you can really do is pray for her. You might also pray about whether it would be beneficial for you to speak directly with this priest. Of course, if he abandons his vows and they have a non-Catholic wedding, the only proper course of action is to refuse to attend the wedding and to abandon all contact with both of them for the rest of their earthly lives. You don’t want your children to be corrupted by apostates.