This talk is split into two parts. I will first examine whether there is sufficient evidence for male ejaculate senescence across the animal kingdom. I will present data from a meta-analysis we conducted on 379 studies, to quantify the effects of advancing male age on ejaculate traits across 157 species of non-human animals. This work shows that there is high heterogeneity in the available data, hence I will try to tease apart the factors that might explain this variation. In the second part of the talk, I will focus on ejaculate and reproductive senescence in the model organism Drosophila melanogaster and try to identify the molecular drivers, contributing factors and fitness consequences of advancing male age for the male, its female mate and for its offspring.