Social relationships directly influence female fitness in primates. While females benefit from affiliating with other females and males, social constraints on females can lead to unequal distribution of affiliative behaviours. In Colobus vellerosus, where females are facultative dispersers and where infanticide pressure is high, do females prefer to affiliate with females or with the resident male? I identified females’ social partners and investigated the influence of maternal relatedness and reproductive status on the rates of affiliation between females and their partners. The majority of females distributed affiliative behaviours towards one female top partner. The reproductive status of females consistently influenced the rates of affiliative interactions between females and their top partners whereas relatedness did not. Lactating females received grooming at higher rates. As relatedness was not a strong predictor of the strength of affiliative relationships between females, I suggest that natal attraction mainly influences partner preferences in this population.