I am not only talking about the narrow meaning of back stab. For example , I often see the text "Although feigning friendship with you..." etc etc, when they declare war on me. Isn't that a backstabbing dialog?
In the latest patch notes, 2kGreg said the following, among other notes:
[DIPLOMACY]
Made backstab routine more transparent (the dialog will clearly state that they are backstabbing you).
Isn't this one of the dialog texts he was talking about? If so, I get that one really often. Especially from the Germans, the Aztecs, and the Greeks. So much that I know and predict that they will do it, no matter what I do in diplomacy, which is what "frustrates" me the most.