The Times He Left
The first time he feels the emptiness is just seconds after their first kiss. Their lips are still just centimetres apart, their rapid breaths caught up in each other and his big, calloused hands still resting on his waist, when someone calls out for Dean. He whispers a "Sorry" and a "We'll talk later" and disappears around the corner, and suddenly he feels it. A tugging on his heart, a hole in his chest, like there's something missing, a part of him that he wasn't even aware of. The feeling goes away when Dean comes back and kisses him again, but it was there, undeniably and painfully there.
He feels it again, a little after their fifth date. They went to the movies, and when Dean dropped him off at home, he promised to call, but he doesn't. He's lying in his bed for hours, staring at the blank screen of his phone, and the emptiness is spreading in his chest, slowing his heart and speeding his breath, until he feels like he can't breathe.
When his phone finally rings, he's gasping for air, and he can't stop the words from bursting out of his mouth. "I love you."
He figures it out the third time, when Dean leaves him in a diner because his Dad wants him to be home in five. The emptiness is something he just feels after Dean leaves. It doesn't even have to be a real goodbye. Just the feeling of getting left behind and his hearts starts aching, desperately trying to fill the gap Dean left.
The next time, it's the first morning in their new apartment. They sleep until noon, and then they eat croissants in bed and kiss the crumbs from each others lips. It seems perfect, until Dean gets a call from his most important client. He leaves in a hurry, doesn't even give him a proper goodbye kiss, just a quick peck on the lips, and the feeling overwhelms him just moments after he closes the door behind him.
When the feeling comes again, it's even worse. They just had their first big fight – he doesn't even remember what it was about – and Dean storms out of the apartment, the door slamming shut behind him. He sits in the living room, wraps his arms around his body and tries to erase the emptiness, tries to fill the gaping hole in his chest, but he can't, he just can't.
The last time he feels it, Dean is standing on the other side of the room, suitcase in hand. His hair is a mess and his eyes are a little bit red, like he silently cried himself to sleep last night, but his face is absolutely calm. "I'm sorry.", he says. "But we can't go on like this. I have to leave. It's for the best."
As he turns around and leaves, he takes the missing piece in his chest with him, and the emptiness takes over, washing away every good feeling and every happy memory.
"No.", Cas whispers into the emptiness of his apartment. "No. It's not."