Late colonial Maharashtra witnessed a proliferation of sex literature that claimed to be scientific. Sexual-health journals and books on sexual science and eugenics, as well as marriage manuals insisting on sex reforms, were produced in Marathi in considerable numbers between 1920 and 1950. Why did sex reformism blossom in Maharashtra? What was reformed in the name of sex and science? What larger purpose did this writing serve in late colonial times? The present research work answers these questions while problematising the Marathi sexual modernity articulated through this literature. In critically assessing sex reforms, my argument highlights the rearrangement of an inextricable nexus between caste and sexuality that shaped late colonial Marathi expressions of modernity. The proliferation of scientific sexuality in this process, I argue, was an upper-caste resolution of the Brahminical crisis over dominating reformism in Maharashtra. To demonstrate this, my work situates sex literature in the context of Marathi caste politics. While explaining the Brahminical crisis and its resolution through analysing sexual discourses of brahmacharya (celibacy), marriage, and obscenity, this work unpacks the making of sex reforms as a journey to create a caste-sexual subject of Marathi modernity—the respectable upper-caste man.