He could still taste Dean's kiss on his lips, bittersweet like the aftertaste of beer remaining on his tongue. Cas can already tell he's wound taut around Dean's pinky finger, his heart at the hunter's mercy. It makes him feel helpless and defenseless and terrified; a sentiment he's been feeling for quite some time as of late. But these stolen moments make everything alright again—they make him feel like it's acceptable to be vulnerable; he lives and thrives for these stolen moments. Days ago he wouldn't have known that; he would have thought the soreness in his heart, the sore tenderness, had taken up everlasting residence there and would never dissolve. But then Dean came along, finding him the way they would always find each other, and that pain vanished almost instantaneously. He lives for this—watching the insipid moonlight gleam against Dean's flushed skin, their lips swollen and raw from kissing, Cas' own heart thumping rapidly in his chest from the close proximity. It's moments like these that make everything okay.
The hint of beer lingers between them, heavy on their breath mixed with the aroma of craving and missing one another. Dean's jade eyes shine intensely in the incandescent light of the full moon, their soft color taking on a near iridescence. Dean leans closer again, pressing a tender kiss to the curve of Cas' mouth, and Cas grins. He can already feel himself getting intoxicated; not on the beer, but on Dean. He feels himself falling for Dean all over again, the way he falls every time he catches a sight of the smirk that tugs at the corners of Dean's lips, or the way he falls every time Dean says his name, or the way he falls every time Cas sees those radiant emerald eyes. He's falling again, despite his mind screaming at him the whole time. "He's going to leave you again," Cas' mind reprimands him, but Cas ignores all reasonableness and sensibility and leans his face against Dean's shoulder before the hunter could move away. Perhaps Dean will leave again—in fact, Cas is certain he'll leave again. But he'll be back; Dean always comes back. So Castiel lets himself fall again, fast and without a single care in the world, because with Dean here, so close to him, nothing else matters.
Tomorrow might be hell for Castiel. It will be like going through withdrawal all over again, like Dean is some addiction. He has become a fixture in Castiel's life; something he subconsciously depends on. He needs Dean, whether he'll ever recognize it or not. Dean might be gone by the time Castiel wakes up; he might linger to say farewell before leaving. Either way, he will disappear, and it will be soon. The thought drives a pang of harm into Castiel's heart, but he pushes it away quickly, because nothing matters other than what's happening right now, right in front of Castiel, with the both of them sitting out in the frosty open air, side by side. Just a night or two with Dean is better than nothing these days, after all. It's better than the horrible, persistent ache of missing him, combined with the emptiness of needing him, combined with the sting of continuously worrying about him—even though Castiel knows that Dean's fine. So Cas just carries on, holding tight to these stolen moments with no intention of ever letting go of them so readily. Quickly, Cas reaches out and grabs hold of Dean's shirt and pulls him close again, kissing him hard.
Deep down, Cas knows that he feels like nothing more than a stop on Dean's road before he continues his wayward journey, one that doesn't require someone as ineffective and wrecked as Castiel. He's alert of the fact that Dean will leave again, and that Cas' last recollection of him for awhile will be the fading taillights of the Impala, but it doesn't matter just yet. Castiel holds on, deepening the kiss and laying down on the grass, pulling Dean down on top of him smoothly and gradually. He's already missing Dean, even as the hunter presses himself down against Castiel, fingers carding through his dark hair as he tries to get even closer. He will always miss Dean, and if he had a star for every scar left on his aching heart, he could create a galaxy just for the two of them to be in tranquility. Dean pulls away, an arm against the grass to prop himself up, his free hand finding its way to Castiel's hip, where he grips tightly and pulls him closer. Dean grins, all teeth and lips and radiance and contentment, and Cas' heart shatters right then and there. He misses Dean even more now, in spite of the fact that he's right there. Seeing him just there breaks Cas' heart, but the gentle kisses along his neck are instantaneous Band-Aids, healing all the wounds. With the smell of beer remaining between them and Dean's slurred moans against his skin, Castiel holds on.