Homer narrates in the Illiad that during a brief stop-over on the small island of Kranai, Helen and Paris consummated their passion.
In the original Greek, Helen's name is Ἑλένη, Helénē, which is the spelling I'm using in this story.
But come, let us take our joy, couched together in love; for never yet has desire so encompassed my soul—not even when at the first I snatched you from lovely Lakedaimonia and sailed with you on my seafaring ships, and on the isle of Kranai had dalliance with you on the couch of love—as now I love you, and sweet desire takes hold of me.
Homer, Iliad 3.442-445
Aphrodite sees them approach the island of Kranai, just off the coast of Lakedaimonia* where Helene left her home, her daughter and parents behind. Such is the power of love. The goddess mounts her faithful goose and descends from Olympos, landing not far from where the couple have stolen away from the ship to find sweet solitude. Aphrodite feels doubt quenching the lust in Helene's loins. She needs to rectify this. Paris is already bright aflame but Paris is a fool and he worries not about the consequences of his rash actions. But a promise is a promise. He will have Helene and she will love him, for better or worse. Aphrodite cannot dispel her doubts but she can intensify her lust for this handsome prince to make her blind to the warnings of her mind. Her presence alone would be enough but Aphrodite feels she wants to participate in this act of rampant eros**. So she reveals herself, naked as the beautiful sculptures the mortals craft of her, the glittering radiance around her proof enough of her divinity. Paris already beheld her in all her beauty but Helene stands open-mouthed at the intimidating beauty of the goddess. Aphrodite smiles at her and takes her hand.
"I am Aphrodite, Risen from the Sea, the Paphian Queen and your ally in love, daughter of mighty Zeus who delights in thunder. Fear not, my child, I will instruct you in the art of love so that you may please him and he will please you."