Selecting a mate is one of the most important decisions an individual makes. Mating decisions can act as a powerful selective agent, resulting in the evolution of complex adaptations. Yet, a major unresolved question in evolutionary biology is why despite the strength of sexual selection, a large variation in sexually selected attributes and sexual behaviors remain. The physical and the social environment in which individuals develop and live strongly contributes to such variation. Indeed, decades of research in sexual selection in studies across and within species have taught us a very important lesson: the context in which mating decisions are taken is key to predict the observed outcome. In parallel with studies of sexual selection, genomic tools have greatly expanded the research horizon of modern evolutionary biology. Traditional approaches were based on targeted differences in a specific gene in comparisons between individuals that presented or not a particular behavior. Such approaches have commonly been replaced by investigations of complete genomes that associate gene networks to specific behaviors. Using these approaches to investigate the link between mate choice and brain transcription is particularly enticing, as it offers the potential to truly understand the genetic basis of mate preferences and how mate preferences evolve. However, integrating genomic tools into the study of behavior and sexual selection has been slow, and this has hampered a genetic understanding of the underlying basis of mate choice variation. Using cutting edge genomic tools in a classic model system of sexual selection studies, the Trinidadian guppy, I will obtain a rigorous understanding of what changes in brain cells when mating decisions are taken across different social contexts. Given the unique approach of this proposal, I expect groundbreaking findings with insights in the dynamic nature of mate choice, prompting further innovative research in this direction.