Mistress Hairbrain and the Courtesan enter. The Courtesan instructs Mistress Hairbrain in the art of appearing chaste and avoiding any traps her husband might set for her. Mistress Hairbrain gives the Courtesan a jewel to present to Penitent Brothel as a promise of her love, which she says she will demonstrate as soon as she manages to escape from her husband's strict guard. When Hairbrain joins them, the Courtesan tells him that Mistress Hairbrain believes that every sin is damnable—an opinion that the Courtesan has been trying to refute. Hairbrain laughs at his wife's alleged moral strictness. He says that sins such as usury, bribery, sloth, pride and gluttony are permissible—the only truly damnable sin is adultery. When the Courtesan exits, Hairbrain orders his wife to follow her instructor's advice faithfully.