Don Quixote Volume 1, Chapter 34
She tells him that his supposed friend is making passes at her and if he doesn't come home she's going to go stay at her parents. Anselmo the Arrogant tells her to stay put -- he'll be home any day now. She now worries that she shouldn't have written to her husband, and that maybe it was something she said or did to cause Lothario to treat her as if she was an unfaithful harlot.
But, Lothario's charm and warmth and tears and sincerity finally win Camila's heart and they become lovers. Anselmo comes home and Lothario says Camila stayed true to him. Camila explains she was just imagining things when she wrote the letter. Leonela knows what is going on and plays it to her advantage by taking liberties in her mistress's home by having her boyfriend stay the night. Lothario spots the boyfriend leaving and thinks Camila is being untrue to him. In a fit of jealousy, he tells Anselmo that he has been keeping the truth from him and that Camila has been responding to his romancing of her while he was away and has promised to sleep with him the next time her husband is away. He tells him to pretend to go away for a trip but instead hide behind some tapestries in that room and see for himself.
Seeing how bad Anselmo feels, Lothario regrets his rash behavior. He then finds out from Camila that it was Leonela's boyfriend and tells her the stupid jealous thing he has done. They devise a plan to use it to their advantage and with her husband watching Camila gives an academy award winning performance of a faithful wife, even using a knife to try to attack Lothario and finally giving herself a small cut that bleeds. Anselmo is joyful again.