sure, but the BBEG also swept her off her feet and made her feel like she is changing him for the better, and that their child together is a blessing that will finally turn him to good. Maybe he let her discover a false prophecy that said just that...
How much detailed information is the party aware of as to the specific situation with the Priestess and the BBEG? What is the position of the Priestess' church on this issue? What about her family, and friends, if any? What are the political affiliations of the Church Of Liberty and the Curch Of Oppression?