In Plautus’ Mercator, the senex amator Demipho lusts after the slave girl Pasicompsa, who is the lover of his son Charinus. Demipho knows nothing about their relationship. He believes that Charinus bought Pasicompsa as a present for his mother while he was trading on Rhodes. In an attempt to gain access to her, Demipho enlists the aid of his elderly neighbour, Lysimachus, who taunts him for his infatuation with such a young woman. Eager to persuade Lysimachus that he is truly in love, Demipho offers to let him cut off his head, finger, ear, nose or lip, or even kill him with love if he is lying about his feelings (308–10):

This hitherto unrecognized list of penalties for adultery not only sheds light on the nature of Charinus’ relationship with Pasicompsa, but also emphasizes the inappropriateness of Demipho's desire for her.Footnote ¹

References to these mutilations appear in poems involving adultery. At Mart. 2.83, a husband amputates an adulterer's nose and ears; at 3.85, a husband cuts off an adulterer's nose, but foolishly leaves the penis intact. In the latter epigram, the adulterer is called ‘Deiphobus’. This is an allusion to the second Trojan husband of Helen, who married her after the death of Paris. In the Aeneid (6.494–7), Aeneas meets the ghost of Deiphobus in the underworld and is shocked by its appearance; the lips, hands, ears and nose have been removed, most likely because of his relationship with Menelaus’ wife.Footnote ² Horsfall suggests that the phrase laniatum corpore toto (495) implies that Deiphobus suffered castration, another penalty inflicted on adulterers in Rome.Footnote ³ This clarifies Demipho's offer to allow Lysimachus to remove a ‘finger’.Footnote ⁴ If digitus is a euphemism for the penis, then Demipho is willing to have his genitals removed, a penalty for adultery mentioned explicitly at Mart. 3.85.Footnote ⁵ His offer of decapitation may allude to the killing of adulterers, while his request that Lysimachus ‘kill him with love’ recalls the practice of raping them.Footnote ⁶ Thus, Demipho's proposed mutilations are all Roman punishments for adultery. This makes perfect sense, because Pasicompsa is essentially the wife of Charinus.Footnote ⁷

Pasicompsa's social status lends support to this conclusion. In the prologue, Charinus says that she was the slave of a hospes who recognized him on Rhodes, invited him to dinner and then sent Pasicompsa to him for the night (98–102). It has been argued that this hospes was the proprietor of an inn, where he hired out prostitutes.Footnote ⁸ He pretended to recognize Charinus in order to draw him into his place of business, and then offered him the services of a prostitute named Pasicompsa. If this were the case, she would be an ineligible marriage-partner for Charinus, because she had worked as a prostitute. The backstory detailed in the prologue recommends another possibility. Demipho was a successful trader, who sent his son to lead his own trading expedition, which turned out to be extremely successful. It is doubtful that Demipho would have entrusted an inexperienced young man with a costly trading venture (87–9), or that a novice would have succeeded in making more money than his father expected (95–6). It is more likely that Charinus had accompanied his father on previous trips to Rhodes in order to gain commercial experience. The hospes, then, could have been a family friend who recognized Charinus from previous business-trips to Rhodes. Pasicompsa was one of his slaves, whom he offered to Charinus for nocturnal entertainment. Having fallen in love with her during the course of that night, he bought her from the hospes. Since she was not a prostitute, and since there is no indication that she had been made available to other men, Pasicompsa was an eligible marriage-partner for Charinus.

Charinus and Pasicompsa have taken an oath to remain faithful to each other and to avoid sexual disgrace (et inter nos coniurauimus … neuter stupri causa caput limaret, 536–7). This type of monogamous relationship, Scafuro argues, is the ideal marital state in New Comedy.Footnote ⁹ Although Charinus cannot legally marry Pasicompsa during the play because she is a slave, Plautus hints that their relationship will change. At the end of the play, Demipho says that Charinus can do whatever he wants with Pasicompsa (988–9), which implies that he can free her and marry her.Footnote ¹⁰ Since other comedies end with a recognition scene and a marriage (Poen. 1344–58; Rud. 1265–9), the audience may have expected a similar resolution for the lovers in Mercator as a matter of course, even though Plautus chose not to portray it on stage.Footnote ¹¹ If this is the case, then Demipho's attempt to corrupt Pasicompsa, who lives in a state of virtual matrimony with Charinus, is tantamount to adultery.

Demipho's list of mutilations is appropriate because he intends to fornicate with a woman who is, for all practical purposes, his son's wife. The humour of this passage lies in the fact that Demipho offers to subject himself to these punishments if he does not love Pasicompsa. Since he does love her, he believes that he is safe from harm. In actuality, these tortures could be inflicted upon him because he does love the girl.