From New Scientist: “Monkeys eavesdrop on neighbours’ orgasmic cries”
Female Barbary macaques (Macaca sylvanus) cry out during sex. When they are fertile, the call stimulates ejaculation in the male. When the females are infertile, they slightly modify the structure of the call, making the male less likely to ejaculate. Fertile females sometimes make non-ejaculatory calls as well.
By the way — these are German monkeys
