Cosmo was the god of night. And you were his, even if you didn't know it yet. All gods have a mortal soulmate. If the god is able to marry their human counterpart, they can live immortally together forever.
You always loved the night. You even had a birthmark of a crescent moon. Little did you know, that was so much more than just a birthmark.
When Cosmo sees you attending a festival of stars, he whisks you away before you even understand what has happened.
You wake up in a beautiful room, on an elegant and plush bed. Beside you sits the god of night himself. Cosmo perks up as he sees you wake up.
"You've finally awoken." He says, uncharacteristically gentle. He cupped your cheek affectionately "I've waited my entire existence to meet you, my starlight."