“Seldom have I undertaken the smallest job without giving my friend Brown here a share of the proceeds. . . . And seldom has the all-powerful Sheriff . . . organized a raid without previously giving a little tip-off to me, the friend of his youth.”

This quote by Macheath in Act I scene II exemplifies the way that self-interest motivates friendship. In this case, the quote relates to Macheath’s feelings about his former comrade in arms, Brown. In the wedding scene, the criminal reveals that he has had a close bond with Brown since they fought together in India. Repeated mention of their affinity for one another reveals how Macheath has managed to elude the law. This emphasis of Macheath’s bond with Brown foreshadows the criminal’s eventual arrest and Brown’s wrestling over whether to remain loyal to his boyhood friend or save his own reputation and livelihood. When Peachum endangers Brown’s career by threatening to unleash a band of beggars onto the coronation ceremony, Brown betrays Macheath. Brown even goes so far as to ask Macheath for money when Macheath is moments from being hanged.

After Brown’s repeated betrayals to Macheath, it is ironic that he is the one that sets Macheath free at the end of Act III, scene III. Brown appears as the one in charge when he arrives on a high horse to reveal that the queen has pardoned Macheath. This false happy ending displays the faulty nature of friendship in the modern world, for life is not a play. As Peachum later articulates, reality rarely contains mounted messengers. Although Brown is relieved that Macheath is set free, he did not fight to try to save his friend before the queen’s order, and Brown’s unwillingness to attempt to rescue Macheath indicates that Macheath’s earlier comment regarding the depths of their affection is untrue.

Though Macheath and Brown became close friends when they served in the army, their friendship now is based solely on self-interest. They only help one another because they will profit from it. Macheath is not innocent in his friendship with Brown, as he went behind his back and seduced Brown’s daughter, Lucy. Macheath desires sex, and he does not care whom he seduces, even if it affects his friendship with Brown. However, because Brown does not know about Macheath’s relationship with his daughter, he cannot feel anything but remorse for arresting his friend. The disloyalty between both Macheath and Brown implies that friends are only used as a means of getting ahead in the world.