Part of me wants Dean and Cas' first kiss to be gentle and sweet. Dean and Cas will finally sit down and talk about everything that's happened, without interruptions or changing the subject. Cas will tell Dean about Naomi, about everything she did to him, about the thousand fake Deans he had to kill. He will tell Dean what broke the connection between him and Naomi. He will tell Dean about the pie. Dean will be silently amazed for a moment, and then he'll start talking. He will tell Cas that he needs him. Not his help or his powers, but him. He needs him to stay. Cas will ask him why. Why would Dean possibly need him? Dean will look away, looking for an easy way out, but realise that there isn't one. He will blush, and actually have trouble meeting Cas' eyes. He will finally say "I love you". He will say those three stupid little words that always give him so much trouble. Cas will stare at him for a long moment, before saying "I love you too, Dean." And then Dean will kiss him, because what else do you do after a confession like that? It will be soft, questioning, because Dean isn't sure if this is okay. He will pull away, and see Cas' wide, startled eyes. He will smile at Cas, and Cas will quirk his lips slightly. Dean will smile wider, and then he will find himself laughing, because he can't contain all of the happiness bubbling up inside of him. Cas will watch him, slightly confused, but he will find himself smiling too, properly smiling, just because Dean is so happy. And then, for the first time, he will laugh.
Part of me wants Dean and Cas's first kiss to be rough and full of frustration. Cas will appear in Dean's bedroom, an apology on his lips, but he won't have time to say it. Dean will push him against the wall and attack his mouth, because he simply can't deal with it any more. He can't handle Cas looking at him like that with his stupid blue eyes. He can't handle all of the things Cas makes him feel. And really, what's he got to lose? If Cas never comes back, he will at least have the memory. He will falter for a moment, but then he'll notice that Cas has grabbed either side of his face and is kissing him just as hard. Dean will bite at Cas' lower lip, almost too hard, because he's still angry. He's still angry at Cas for leaving. He will twist his hand into Cas' hair, pulling slightly. Cas will turn him around, pushing Dean up against the wall, still kissing him hard. When Dean finally pulls away, out of breath, he'll look at Cas with a kind of wonder. He will wonder what the hell just happened. He will wonder how Cas is such an impossibly good kisser. He will wonder how Cas' hair can be even more of a mess than usual. Dean will look into Cas' eyes, see the surprise in them. And then he will kiss him again.
Part of me wants Dean and Cas' first kiss to be needy and desperate, because it's the end of the line and one, or both, of them is about to die. Dean will reach out for Cas, getting a firm grip on his hand. He'll look at Cas and see him fading away. "Cas no," he will say, voice hoarse, "Don't leave me here". Cas will look up at Dean, squeezing his hand "It's alright Dean," he will say, voice cracking. Dean will growl, because no it fucking isn't. He will grab Cas' face and beg him to hold on, beg him to stay. Cas will look up at Dean, at the man he rescued from hell all those years ago. He will marvel at what they've become. Dean will look down at Cas, becoming more and more desperate. "Don't leave me here you son of a bitch," he will say. He will grit his teeth for a moment, before finally spitting out the words, "I love you." Cas will stare at him, shocked, before squeezing his hand again, "I love you too," he will whisper. Dean will freeze, too amazed to move, before leaning down to kiss him. It will be raw and desperate and passionate. Dean will pull away, panting heavily, still holding his hand. Cas will try to hold on, but he will continue to fade away. "Dammit Cas, stay with me," Dean will say. Cas will quirk his lips at that, reaching up to touch Dean's cheek. He rest his hand there for a moment, before moving it to Dean's left shoulder, where the handprint used to be. "Goodbye Dean," Cas will say, just before the life fades from his eyes. The tears will fall from Dean's eyes as he slides an arm under Cas' shoulders and pulls Cas towards him. He will hold on, tears running down his cheeks. He will kiss Cas on the forehead, and he will make a promise, "I'll find you."