It's funny (but also gives me a sad feeling at the same time) when Kitty promises that she'd behave if she went to Brighton---how often do we see Kitty do anything that establishes her independence from Lydia in this novel?---and Mr. Bennet responds by really clamping down on her. "No, Kitty, I have at last learnt to be cautious, and you will feel the effects of it." Etc. Except that we know by his own admission that this will fade, and it's made clear enough that it's mostly a joke with "Kitty, who took all these threats in a serious light, began to cry."

Of course, Kitty's promise probably came from just that feeling of, "Oh, now that Lydia messed up I won't be allowed to do anything!" The girl can't catch a break. I always laugh reading the scene, but I also kind of ache for just what a dysfunctional relationship Mr. Bennet has with his daughters. (And yes, I include Lizzy in that even though she's his favourite, but he wouldn't take her advice about keeping Lydia at home.) It's almost as if Kitty is making the sort of overture that could get her included in the magic circle of her father's affections---saying that she'd behave well, or at least better than Lydia---and she gets pushed away. Funny dialogue, but sad.