Once upon a time, the goddess Venus had helped Hippomenes, the son of Megareus, by giving him three golden apples, due to which Hippomenes won a race against the fleet-footed virgin Atalanta, the daughter of Schoeneus, and Hippomenes married Atalanta.
But the ungrateful Hippomenes forgot the help of Venus. Neither did he offer any prayer of thanks to Venus, nor did he offer sweet frankincense at her altar. Such unthankful conduct made Venus furious and being thus slighted, she thought of making an example of them, so that she may not be neglected by any one in future.
When Hippomenes and Atalanta were traveling in a forest, they came across an ancient temple, which glorious Echion had long ago constructed, in due payment for a vow to Rhea, the mother of the gods. Weary from their traveling and needing rest, when they saw the old temple concealed in the forest, they gladly relaxed in the sacred place. At that moment, Venus caused the heart of Hippomenes to be seized with an irresistible passion. Atalanta responded to his passion, and the lovers looked around for a place, to calm their burning passion.
Very near to the temple, there was a pumice covered place that resembled like a cave. The past had hallowed the place with religious veneration, and within the shadows of that cave-like place, a priest had installed several wooden idols of ancient gods. Hippomenes and Atalanta, inflamed with passion, entered this holy place and defiled it.
The images of the ancient gods turned their eyes away. Cybele, the tower-crowned mother goddess, was furious and initially, thought of plunging the guilt-ridden pair under the waves of river Styx, but this punishment seemed light compared to the weight of their crime. Hence, she changed their forms to fierce lions, who roamed the woods as a suitable bridal-place for their vicious natures, and who could only be harnessed by Cybele.
Excerpt from the book “Once Upon A Time-II: 150 Greek Mythology Stories” by Rajen Jani