The Marquise de Merteuil, meanwhile, accepts Valmont's apologies and protestations (Letter One Hundred and Thirty-one). She remains skeptical, however, about whether they can be happy together again.
Tourvel replies to Rosemonde (Letter One Hundred and Thirty-two) to tell her that she is now thoroughly debauched and also thoroughly happy. It is a strange and sinful combination, and as such, she will trouble Rosemonde no more by writing to her of it.
Valmont promises the Marquise that he is not in love with Tourvel in Letter One Hundred and Thirty-three and swears that he will soon send her proof of his affair with the Présidente. But the Marquise is not so easily satisfied. In Letter One Hundred and Thirty-four, she accuses him of being in love with Tourvel and hiding it from himself. She suggests that they just be friends in the future, since Valmont's lingering feelings for the Présidente would get in the way of anything more. She also announces that she has now entirely ended her affair with the Chevalier de Belleroche.
Indeed, Valmont has ended his affair with Tourvel very suddenly. The Présidente writes to Madame de Rosemonde (Letter One Hundred and Thirty- five) to tell her the sad news: Valmont left Tourvel without warning at home, and she later saw him with a prostitute. The Présidente then writes to Valmont (Letter One Hundred and Thirty-six) to tell him never to darken her doorstep again and to ask him to return her letters.
Valmont replies (Letter One Hundred and Thirty-seven) to tell Tourvel that appearances have deceived her. He begs her not to end their affair so suddenly.
In this exchange, the theme of illness and doctors and the comparison of love to an illness appears for the first time. The Présidente de Tourvel is in correspondence with Madame de Rosemonde, whose rheumatism often prevents her from writing her own letters. Madame de Rosemonde writes (Letter One Hundred and Twenty-six) that, ill as she is, she herself will serve as Tourvel's "doctor" ("Médecin") during this period of grief over love. It is interesting that Rosemonde does not offer herself up as confessor or comforter, and that the suggestion that love is a sickness proves so convincing—soon Tourvel will indeed die of love for Valmont. What he sought to describe as a kind of religious devotion or sacrifice, Madame de Rosemonde wishes Tourvel to view as an "indisposition." Illness can be cured, but one must devote oneself to one's religion without the hope of return.