Tanzania, along with several other African countries, is experiencing a national mining boom, which has prompted hundreds of thousands of men and women to migrate to mineral-rich locations. At these sites, relationships between the sexes defy the sexual norms of the surrounding countryside to embrace new relational amalgams of polygamy, monogamy and promiscuity. This article challenges the assumption that female prostitution is widespread. Using interview data with women migrants, we delineate six ‘wifestyles’, namely sexual-cum-conjugal relationships between men and women that vary in their degree of sexual and material commitment. In contrast to bridewealth payments, which involved elders formalising marriages through negotiations over reproductive access to women, sexual negotiations and relations in mining settlements involve men and women making liaisons and co-habitation arrangements directly between each other without third-party intervention. Economic interdependence may evolve thereafter with the possibility of women, as well as men, offering material support to their sex partners.