The first time Dean walked into the living room of the Batcave to find Castiel on the couch watching some documentary about birds, he was concerned. The guy had just lost his own wings – seeing a bunch of eagles in flight had to be rubbing some salt in the wound. But when he said as much, the former angel insisted that the program wasn't giving him any kind of emotional stress. So Dean popped the top off his beer and plopped down on the far side of the couch to watch the last 20 minutes with him.
Of course, he hasn't quite anticipated Castiel's commentary. Apparently the guy had had enough personal encounters with red-tailed hawks to know that their wingspan can grow up to sixty inches, versus the Animal Planet claimed fifty-two. He also corrected their segment on vultures – "they don't vomit to fend off predators, but to lighten the load in their stomachs so that they can fly" – and that was something that Dean really, really didn't need to know. But – God forbid Sam ever find out – the hunter found the whole thing quite interesting. So the next day when he found Castiel entranced by a show about jungle cats, Dean joined him for that, too. And the day after that, when it was a special marathon about whales. And then the one about snakes the day after that.
It became a routine; on the long days between hunts, Dean and Castiel would camp out on the couch with some sort of nature documentary on TV. Eventually Dean figured he knew more about birds and fish than demons and vampires, which was a sort of scary thought. But he liked the rhythm they had; beer in one hand, remote in the other, sprawled out over the couch together. As the weather started getting colder, they started huddling up with blankets and using the old fireplace. And once it got into the especially cold months, the ends of the couch saw less and less of the two men as they migrated to the center to share warmth.
Neither of them appeared to notice their increasing closeness. At least, not until they were watching a commercial about "killer tarantulas" and Castiel murmured something about their largest prey being small birds and Dean turned his head and suddenly they were inches apart and the hunter could see every tiny blemish in the ex-angel's skin. That is, if he wasn't so distracted by the mesmerizing blue eyes twinkling with something he had never seen before in his friend – in fact, the last time someone looked at him like that, he got laid and – oh. Oh. He caught the movement of a pink tongue trailing over a chapped lip in his peripheral vision and then he couldn't look away, was so enraptured that it actually looked as if those now saliva-slicked lips were getting closer, leaning in toward him, and then –
The kiss was brief, simple, just a light press of mouth to mouth. One of Castiel's hands came up to rest on Dean's chest, but both of Dean's hands remained in his lap, fingers frozen, wrapped around handfuls of wool blanket. It ended so fast, the hunter hasn't even registered it before it was over, but it was perfect. Castiel returned his attention to the television screen and Dean continued to stare blankly at the side of his face for a moment before doing the same.
After another minute or so, Dean pulled his arm out from where it was sandwiched between then and placed it tentatively on the ex-angel's shoulders. Castiel sighed into it, and they seemed to melt together along the line where their bodies were touching. Dark hair tickled the underside of Dean's chin, his lips tingled with the aftertaste of satisfied anticipation, and on the television, an elephant trumpeted its approval.