You have to counteract the trick she is trying to play on you by playing one on her. So start by not making such a display of your melancholy, so as to make her believe your mind is not continually on Danceny. She will be persuaded of it so much more easily as this is the usual result of absence. And she will be all the more pleased with you, for she will find she has occasion to congratulate herself on her prudence, which has suggested to her this course of action. But if she still has her doubts and, persists in putting you to the test, and comes to discuss marriage with you, like the well-born girl you are, just contain your feelings and give in completely. For what risk do you run? As far as husbands go, one is just as good as another. And even the most unaccommodating is much less of a trial than a mother.

(Letter CV, The Marquise de Merteuil to Cécile Volanges)