Just spotted this yesterday: "You know what you did" relation modifier with the Thalans.
I don't quite remember what I did 
It was while playing the campaign, so I was wondering if it has something to do with the backstory (Thalans coming to prevent the crusade）。 I don't remember seeing it during normal play.
http://steamcommunity.com/sharedfiles/filedetails/?id=609881824