Polyspecific associations are well documented, but have rarely been observed in strepsirrhines. In this study we present a unique affiliative association between a female ring-tailed lemur (Lemur catta) and a group of southern bamboo lemurs (Hapalemur meridionalis) in south-east Madagascar. Our main research focused on H. meridionalis; however, due to the presence of the L. catta we treated her as a group member, including her in the focal sampling of Hapalemur social behaviour. We also recorded ad libitum data on all food species/items and any unique events or occurrences. Among observations, both species appeared to have a mutual understanding of vocalisations, behavioural synchronisation, dietary overlap, and possible service exchange, e.g., grooming. We also observed the L. catta occasionally attending to the bamboo lemur infant. This included grooming, baby-sitting, and even transporting the infant. The behavioural flexibility exhibited by both species has allowed the successful integration of the female ring-tailed lemur.