Early on in my career m, I dealt with a controlling overbearing mother of the bride, who overrode her daughter’s wedding cake flavor choices in favor of what she (the MOB) wanted…
After the second (free) cake consultation/tasting/design work up (for which I spent time drawing up design samples) I began imposing a Joy Charge (because MOB’s name was Joy and because it was the payment for the “joy” of doing business with her). I called it a revision charge.