Back when the earth was young, Gabriel had been sitting up in heaven looking over a new hymn he was writing for the heavenly choir when his little brother Castiel came up to him with a problem. It was clear the young fledging was nervous. Castiel shifted from foot to foot and his downy wings trembled. Castiel was just a teenager in angel years. His wings scarcely hung down to the middle of his back and were still the mottled gray color that all fledglings' wings were. They wouldn't become the large and impressive specimens made of silky inky black feathers they would be until much later.

"Well little brother, what can I do for you?" Gabriel inquired with an amused look on his face.

"Umm, Gabe? Can you, uh, help me build a nest?"

Gabriel chuckled. So that was the problem! Little Castiel was growing up and was getting ready to enter his very first nesting season.

"Of course little brother. I'll gather the materials and show you where to put them, but you'll have to build it yourself. That's how you'll learn."

Gabriel traveled throughout heaven and earth, gathering the softest and most beautiful things he could find for his brother to build his first nest with. Once all the materials were gathered, Gabriel guided Castiel into the fine art of nest building.

"Just like that. Okay, now use your grace to make it stick together. Good."

It took quite awhile and was rather lopsided when it was finished, but for a first nest, it wasn't bad. Later that night Gabriel helped Castiel climb inside it. Castiel curled up into the soft, warm nest. Because his wings weren't large enough to cover him yet, Gabriel had brought a blanket and tucked around him. After brushing a kiss upon the top of his brother's head, Gabriel left. Off and on through the night and through the rest of Castiel's first nesting season, Gabriel often heard the sound of his little brother pleasuring himself and moaning softly as he did so since he had no mate at the moment.

Now many years later, they were in the same situation once again. This time though they were in a dingy motel room somewhere outside of Phoenix. Castiel still shifted nervously from foot to foot and his black, silky wings trembled as he once again asked his brother for assistance with building a nest.

"It'll be my first time with Dean and I want it to be perfect. Please my brother. Help me again?"

Together Gabriel and Castiel built a large nest on the king size bed Castiel shared with Dean. They built it out of whatever towels and blankets they could scrounge up along with a few pieces of Dean's clothes. In the end, it was quite a nice nest.

When Sam and Dean returned from a supply run, both of them were rather surprised to see the large nest and a naked Castiel inside it. The matter was quickly explained and as soon as Sam got the jist of what was going to happen with his brother and Castiel, he wasted no time in grabbing Gabriel's hand and scooting off to their own room.

Late that night as Gabriel drifted off to sleep with Sam snuggled up against him, he could hear the sounds of Castiel and Dean as they made love yet again. In the darkness, Gabriel smiled as sleep claimed him. He was happy his cherished little brother had such a loving mate.