Anteros
The twin brother of Eros

Anteros is love avenged or returned, "mutual love" or "reciprocal love". Aphrodite is called the mother of the "Twin Loves" (Eros and Anteros) (Ov.Fast.4.1). The story of Timagoras and Meles illustrates the nature of Anteros:

The Athenian Meles, spurning the love of Timagoras, bade him ascend to the highest point of a rock and cast himself down. Timagoras, who was ready to gratify his beloved friend in any of his requests, went and cast himself down. When Meles saw that Timagoras was dead, he suffered such remorse that he threw himself from the same rock and died. For this reason some people in Athens worshipped Anteros as the avenging spirit of Timagoras (Pau.1.30.1).

According to Cicero, Anteros was the son of Mars (Ares) and "the third Venus" (Cic.ND.3.60). For Cicero's confusing genealogies and duplications of the gods, see Graphic Guide to Cicero's De Natura Deorum.