"Luci, what are those?"
"Those are stars, Cas."
"Stars?"
Lucifer smiled. His brother had such curiosity. He knew that it would become an issue when Castiel grew older, but it was adorable in a fledgling.
Right now was a bad time for star gazing. Father had just created humans, and He didn't appreciate the fact that Lucifer wasn't a big fan of the new species. Lucifer knew that he wouldn't be in heaven for much longer. He hoped that Michael would help him, but that brother was too blindly obedient to see Lucifer's point of view.
He hoped that Michael might help him for Cas' sake. He was just a child, a mere one thousand years old, and Lucifer was the only one who would spend time with him. It wasn't because of his curiosity, it was because of his wings.
Cas had beautiful wings. They were larger than most were at that age, but there wasn't anything wrong with them except the colour. Most angel's wings were white or ivory, and there was the occasional gold in a few garrisons. But no one had wings like Castiel.
Castiel had black tipped wings. They were a beautiful white for the bottom half, but as they got higher, they turned into a dark blue, and then black.
The blue was what got everyone weirded out. It sort of made sense, because if Cas had a vessel that looked as close to his true form as possible, it would probably have raven black hair and bright blue eyes.
But no angel ever had blue wings. Or green, or purple, or orange, or any other colour. Lucifer had seen someone with grey wings once, but he got weird looks too.
Everyone thought Cas was wrong, or that he would do something terrible when he got older. So, they avoided him. Some wouldn't even look at him, but some just wouldn't interact with him. They would say the occasional greeting, but no more.
Not that he noticed. Lucifer was all that he seemed to need. Gabriel would come by a lot too, but Lucifer was closest to the fledgling.
"Yeah, stars. You can only see them on Earth. That's why I took you here. Those are what Father got the idea of us from. After He made the heavens and the earth, He looked up to His sky's and said, " My children will burn as brightly as those stars. " And we do. So much that those new humans down here can't look at our true forms. But, Father realized that, as great as we were, we had no emotions. No love, no fear. So, he made more children. Humans. And, according to Him, they are the ones who burn as brightly as the stars. But, they aren't the only ones, Cas. You burn as brightly as those stars."
He looked Cas in the stomach. Cas giggled.
After some time, Cas fell asleep. As Lucifer lay beside him, his head on his shoulder, he sighed.
"Even when I'm stuck here forever, I will remember how brightly you burn, Castiel."