She was now struck with the impropriety of such communications to a stranger, and wondered it had escaped her before.
Elizabeth, however, had never been blind to the impropriety of her father’s behaviour as a husband.
She represented to him all the improprieties of Lydia’s general behaviour, the little advantage she could derive from the friendship of such a woman as Mrs. Forster, and the probability of her being yet more imprudent with such a companion at Brighton, where the temptations must be greater than at home.
Amazed at the alteration of his manner since they last parted, every sentence that he uttered was increasing her embarrassment; and every idea of the impropriety of her being found there recurring to her mind, the few minutes in which they continued were some of the most uncomfortable in her life.
It soothed, but it could not console her for the contempt which had thus been self-attracted by the rest of her family; and as she considered that Jane’s disappointment had in fact been the work of her nearest relations, and reflected how materially the credit of both must be hurt by such impropriety of conduct, she felt depressed beyond anything she had ever known before.
Every idea that had been brought forward by the housekeeper was favourable to his character, and as she stood before the canvas on which he was represented, and fixed his eyes upon herself, she thought of his regard with a deeper sentiment of gratitude than it had ever raised before; she remembered its warmth, and softened its impropriety of expression.
There are no more uses of "impropriety" in the book.