He lied when he said at his wedding that Camilla would never be queen
To be strictly accurate I believe it was "spokesmen" who said that rather than Charles himself
AFAIK the closest he ever came to a recorded remark was in a response to a child who asked him about it, when he stuttered something along the lines of "Umm well ... errr ... that could be ... we'll have to see"
Now in fairness some may regard that as a suitable sort of remark to have to make when it comes to a future queen, but as a Republican who believes that if we have to have them at all there should surely be some sort of dignity it's not my view