The deceased apparently tumbled over the edge in Carapungo, a neighbourhood in the north of Quito, Ecuador’s capital.
Calderon Police District Operations Chief Cristhian Trujillo told local reporters the couple had thrown a party with friends at home.
The 28-year-old female victim, who has not been named, had reportedly thrown the party, to celebrate her imminent graduation.
After the get-together, the couple reportedly had sex on their third-floor balcony, before falling three floors to a neighbour’s terrace below.
She had apparently heard an unusual noise seconds earlier, and had gone out to investigate.
A heartbroken relative of the female victim told reporters that the deceased woman was the mother of an eight-year-old girl.
Local authorities launched an investigation into the deaths.