To the Romans, February was also sacred to Juno Februata, the goddess of febris ("fever") of love, and of women and marriage. On February 14, billets (small pieces of paper, each of which had the name of a teenage girl written on it) were put into a container. Teenage boys would then choose one billet at random. The boy and the girl whose name was drawn would become a "couple," joining in erotic games at feasts and parties celebrated throughout Rome. After the festival, they would remain sexual partners for the rest of the year. This custom was observed in the Roman Empire for centuries.
State sanctioned sex partners. No wonder Rome lasted for so long.