„Dean?", Cas asked, staring at him with such pain that Dean couldn't bear to look at him.
"It's okay, Cas. It's okay," Dean murmured and pulled the angel into a hug.
"No it's not. You can't just… go off again on some suicide mission, I can't… I can't…", he stuttered until his voice finally broke.
Dean closed his eyes. It was just too much to see him, Cas, on the edge of crying. He was an angel, he… why was he so important to Dean? Why didn't he let Dean go? It was their only chance.
"We don't have a choice, baby," whispered Dean and did a grimace to keep himself from tearing up. He didn't want to cry, not in front of the others.
I can do this. I have to do this.
"You have to understand, Cas. It's just… I'm the only one who can get close enough to her and to trigger the bomb. It has to be me."
Silence between them. No one spoke, but Dean could feel Cas' heartbeat, fast and nervous. He himself was struggling to stay calm, struggling to stay the Dean who could fight, the Dean who would give up anything to save others. It was just… sometimes even he was scared. Sometimes even he was tired.
"I could come with you"
Now it was Dean's turn to look surprised. Did Cas just really said that? He knew Dean wouldn't allow it. Dean didn't want anyone to get hurt. No one should suffer, especially not Sam or Cas.
"No! No, you you can't do that. You're far too important! Besides… who will look out for Sammy if not you. You're the only one I trust. You have to promise me, Cas. Promise me you'll look after him."
"But Dean, I…"
"Please, Cas. It's the only thing I'm asking for. Look at it as my dying wish."
Cas sighed but then nodded. Dean felt lighter now, knowing that his brother would be protected.
"But Cas, there is one other thing."
Cas stared at him and Dean was afraid he would get lost in his deep ocean blue eyes. Suddenly Dean was very aware of the others looking at him and Cas. But there was no other choice, he had to do it. He had to finally admit, what he was feeling, to finally show what he wanted most: Cas.
He closed his eyes and moved forward. To Dean's surprise Cas knew what needed to be done and finished off the last centimeters that separated them and finally their lips met.
For such a long time Dean had wished for that moment and now it was there. To know that this was his last kiss, and the last time they would see each others, it broke something in Dean, but it made the kiss far more bittersweet. And Dean would remember it, as long as he lived, which wouldn't be long presumably everything went right, but still, he was glad he did it. He was glad he finally kissed his angel, because that was the only way he could say goodbye to Cas. Anything else wouldn't have been the same and the kiss was the only thing that mattered.