Cas tries to claim the cat just followed him home, but Dean seriously doubts the integrity of his story when the offending intruder is curled up contentedly in Cas’ arms, purr echoing through the bunker in a soft rumble that Dean does certainly not find endearingly reminiscent of Cas himself.
"It’s a large facility, Dean, you probably won’t ever cross paths," is all Cas says about it, and, as if on cue, the cat jumps out of Cas’ arms and struts across the hall to settle itself on top of on of the library’s large bookcases.
Dean sighs, glares at the cat, then turns to point his finger accusingly at Cas. “If it so much as touches the door of my room, it’s out,” he states. Cas nods indulgently, which perhaps should have been the first sign that Dean had already lost this battle.
And he would continue to lose more, because apparently the cat was as much determined to flaunt itself in front of Dean as Dean was to avoid it at all costs. First it claimed the library as its stomping ground, then the kitchen, followed by the war room, until almost the whole multi-level, massive complex was claimed in the name of Cas’ cat.
"It’s taunting me,” Dean complains one morning over breakfast around the large table in the middle of the library. “It even followed me into the shower room. The shower room, Cas! I thought cats were supposed to hate water!”
"Sometimes creatures will surprise you in their nature, Dean," Cas replies calmly, eyes fixed on a book propped open on his lap. He looks up when the creature in question jumps up to obscure his view of the pages. His mouth twitches teasingly, though the sentiment in his eyes is thoughtful when he says, "The fact that I am here at all should be proof of that. "
It was upon that moment, then, smiling back at his friend, that Dean realised he hadn’t really lost anything at all. He’d actually kinda won a lot. And so, after two long weeks of rejecting his new feline tenant, Dean kicks his bare feet up onto the table’s dark wood surface. “The cat can stay,” he finally concedes, and adds as a jokingly delivered, but genuine afterthought, “And if it needs to be said, you should, too. You know, if you want.”
"Of course, Dean," is all Cas replies with, a warm smile gracing his lips. And really, nothing else needed to be said.