The past 15 years have seen dramatic changes in social norms around sex and sexuality in the UK and worldwide. In 2011, the London Natural History Museum (NHM) contributed to these debates by opening the temporary exhibition Sexual Nature, which aimed to provide 'a candid exploration of sex in the natural world' whilst also drawing in an under-represented audience of young adults. Sexual Nature provides an opportunity to explore Macdonald's 'politics of display' in the mutual construction of (public) scientific knowledge, society and sexuality, at a time of intense contestation over sexual norms. Whilst Sexual Nature both reflected and contributed to major reframings of sexuality and what science can say about it, the assumption that it would be possible to present this topic as morally neutral, reliable and uncontested, in line with traditions of public science, proved to be problematic. The language of the exhibition moved back and forth between human/animal similarity and difference, and between scientific and cultural tropes as the NHM tried to maintain epistemic authority whilst also negotiating the moral boundaries of acceptable sexual behaviour. The topic of sex pushed the museum far beyond its usual expertise in the natural sciences towards the unfamiliar territory of the social and human, resulting in an ad hoc search for, and negotiation with, alternative sources of expertise. Boon et al.'s co-curation approach to exhibition building has the potential to extend the NHM's audience-driven strategy, whilst also producing a more coherent and nuanced exhibition about the science of sex.