The Goddess of Beauty, Aphrodite, was originally married not to the War God in mythology, but to the Smith God Hephaestus. However, the nature granted by her godhood made her unwilling to be bound by marriage, and her husband's ugliness and disability intensified her aversion. So quite naturally, she secretly sought her own "love," and the handsome and robust Ares naturally became one of her most frequent clandestine lovers.
In this process, their illegitimate child, the Little God of Love who likewise left behind many legends, seemed to have some connection with that Primordial Deity from the creation of the world. He too was known as "Eros" in mythology and had authority related to desire, making it hard to believe there was no relation between them—of course, apart from being called Eros, he had another name well-known, bestowed upon him by the Romans—"Cupid."
