Cas decided to give himself to Dean for Christmas. (Sam had been watching Christmas romcom movies with him, and it seemed to be a theme) They'd had a rather terrible hunt and he was hoping to cheer Dean up and make him aware of his affections. He'd heard of snow angels and found the idea sort of amusing and he just likes Christmas lights. He likes how they glow and flicker and how somehow this causes people to feel joy.
So he situated himself out in the snow and spreads his wings out behind him to print them in the snow and texts Dean. He tells him where to look for him to come get his Christmas gift.
He's waiting for Dean in the snow and he sort of drifts off a little, he's kind of powered down, still recovering from an injury he recieved during their last hunt, and it's a really lovely quiet night. The snow is cool against him but he still doesn't really get cold. It's a clear night where he can watch the stars and the softly flickering lights are calming.
Then Dean finds him. He sees the wing imprints in the snow and where Cas' injury has bled through his shirt a little since he laid down. He freaks out.
His first thought is that somebody has killed Cas and cruelly sent him a message so he'd be found. That it was a Demon with a horrible sense of humor that left Christmas lights flickering around a fallen angel.
So Dean FREEZES when he sees. He whispers "Cas?" quietly because that's as much as he can get out. Cas is so drowsy and zoned out that he doesn't hear Dean until he's collapsed to his knees and is crying.
That has Cas sitting up quickly because Dean should not be crying. He can't quite figure out what he did wrong but he's moving to be in front of Dean to calm him down. This is not at all the reaction he expected.
"You scared the shit out of me, man" Dean says as he punches Cas in the arm. Then he's leaning forward to grab hold of the edges of Cas' coat and pull him closer. He leans his forehead against Cas' shoulder and just breathes, trying to calm down.
Cas is happy because Dean is rarely affectionate and he really does like the feel of him in his arms. He wraps his arms around him and tries to explain,"It didn't occur to me that it could be interpreted like that. I just wanted to give you your Christmas gift, Dean"
Dean lifts his head and one of his hands lets go of Cas' coat and presses against where his injury has bled through his shirt "What the hell kind of Christmas gift was that?!"
Cas frowns a little and blushes. "It was me."
It takes a moment for Dean to get it. And that's how Cas and Dean's first kiss happens. In the snow with tears on Dean's face with Dean clinging to Cas' clothes and Cas wrapping his arms and wings around him to try and stop his shivering.
—-
It's twenty minutes later as they walk back to the house, their lips slightly swollen and their fingers tangled together as they walk closely side by side that Dean thinks to ask, "Why were you lying on the snow like that anyway?" He tugs gently on the string of lights in Cas's other hand.
Cas blushes again as they walk up the porch, "I was a snow angel."
Dean laughs so hard that he has to let go of Cas and sit down. That's how Sam finds them, Cas looking at Dean fondly and Dean laughing so hard that he has new tear tracks on his face.