'Nineteen thirteen was an extraordinary year for Stella Miles Franklin. Alongside her hectic schedule with the National Women's Trade Union League in Chicago, Franklin worked on a variety of manuscripts, including the suffrage play “Aunt Sophie Smashes a Triangle”. I focus on this play about male adultery, contextualising it in her personal relationships and intellectual life, especially in the ways Franklin's interest in social purity, feminism, and the influence of Charlotte Perkins Gilman coincided with moral movements abounding in Chicago during 1913. Energised by the progressive literary endeavours of the period, Franklin makes three important points in this protest play about male adultery that include: the degeneracy of masculinity that leads to male susceptibility for adultery, the dangers of domesticity that help explain male infidelity, and the necessity of women's economic independence and solidarity to survive the realities of male adultery in society. In this latter claim, Franklin subverts the polarisation of wife and mistress and presents women as allies united in resisting male sexual transgressions.' (Source: Author's abstract)