Little God by R. Cooper

Melis, the fledgling God of Desire in All Its Forms, is of course aware of the famously beautiful and famously unwed King Antero. Though the human king has been approached by many suitors, all have been intimidated by the strength of his remarkable heart. The lonely Antero has been praying for a companion, a friend who will stay by his side if he is not meant to find the other half of his soul. For years, he has been making those prayers to Melis.
Known by many names including Melis the Prankster and Melis the Cruel, Melis is blamed by humans and gods alike if he answers their wishes—and if he doesn’t—and almost never thanked for the stories that turn out well. He has listened to Antero’s yearning without responding, secretly pleased to have the noble king’s devotion for himself, but mostly convinced there is no one on earth who could ever be Antero’s equal.
But when some of the elder gods insist Melis would serve the world better if he knew anything of desires for himself, the little God of Desire decides to visit the private chambers of the king and finally respond to his most faithful servant—only to find himself wanting to answer the king’s wish in a more personal way than he’d anticipated. Melis might be divine, but one clever human king is more than a match for him, especially once Antero decides it’s time for Desire to learn something of Love.