Dean pressed the knife harder against his skin, pressing his lips together to hide the gasp of pain. 'I'm sorry, Cas.' He breathed. The blood trickled down his wrist and he squeezed his eyes shut, hating himself more and more. 'Dean? Dean.. what are you doing?' Cas' voice rang out from behind him. Dean dropped the knife and leapt to his feet, spinning round. 'Cas!' he yelped, hiding his arms behind him, 'Cas what do you want?'
'I thought.. I heard a call.' Cas said, looking confused as he cocked his head to the side. Dean cursed under his breath and shook his head, 'No, Cas, I didn't call you.' He muttered, looking down in shame. 'Where's Sam, Dean? And what are you doing? What's the knife? Dean?' Cas asked, stepping forward in concern. Dean stumbled backwards, kicking the knife under the bed, 'He's at the store. And nothing, I was just sharpening it, that's all.' Dean gritted his teeth as he lied, his wrist seeming to throb with pain as the words fell out of his mouth. 'Show me your arm, Dean.' Cas commanded, and Dean closed his eyes as he helplessly extended his arms out in front of him. Cas moved forward and took hold of Dean's left arm, gripping it hard enough to make him wince. 'Why would you do this? Why?' Cas asked, staring into his eyes in genuine confusion.
Dean collapsed on the bed, resting his head on his hands. 'Son of a bitch.. I don't know Cas, okay?' Cas stood silently for a moment, before slowly moving to stand in front of Dean. He hesitated, the slowly dropped to his knees. 'Don't do it again. You've had enough hurt for one lifetime, you don't need to give yourself any more.' He gripped Dean's hands tight and gazed into his sad eyes. 'Promise me.' He whispered.
Dean said nothing. He was frozen solid the second Cas had knelt in front of him. Thousands of emotions were pounding through his body as he watched Cas' lips, overwhelmed by his desire to place his own lips against them. He wanted nothing more than to cling to the delicious form in front of him and disappear into their own heaven. But he couldn't. So instead he nodded once and breathed, 'I promise.' and pushed the kneeling angel away.
Cas climbed to his feet and watched Dean for a moment, a little confused. He'd been so sure Dean would kiss him... so hopeful. Had he misread him and crossed a line? Shaking his head minutely, he straightened himself. 'Remember, Dean, I'll always answer your call. Always.'
By the time Dean looked up, the angel was gone.