The Sharpie slid across the skin of his arm, gliding over the pale white limb.
The marker was green - Castiel noted that it matched the shade of Dean's eyes - and was writing the eldest Winchester's name.
The blond was staking his claim on the angel - his angel - just as Cas had claimed him. Sure, a marker pen wasn't as permanent as the hand-print scar on his upper arm, but it was blunt, to the point, and Dean had control over the shape.
Knowing Cas, he could probably draw a dick, and he wouldn't care. Probably wouldn't even realise.
His forearm was where Dean was making his mark - easy to show off to people, but easily covered by the long sleeves of the layers of clothing the angel always wore.
Speaking of which, the tan trench coat that Castiel wore religiously was laid across the Winchester's lap, keeping it from the angel it belonged to.
The angel had also removed his suit jacket, and rolled up both sleeves of his dress shirt.
Dean had rarely seen the man so exposed - the only time before that, was when he got Dean to carve the angel-banishing sigil onto his chest, and, at that moment, the blond was too worked up about Sam and Adam and Michael and Cas - Cas, who didn't believe and trust in him - to be able to take the sight in.
After he finished his branding, he shifted his body to properly face the angel. His hands moved to the buttons along Cas' shirt front, and worked his way through undoing them, pushing the shirt off the angel's shoulders when all buttons were undone.
Without the shirt - and the other many layers he usually wore - Cas was extremely muscular. Under his layers, there were hidden muscles and a six-pack, and Dean almost swore in arousal.
But, he was going to take it slow with the angel. They had time. All of eternity. Because, as both of them knew, no matter what Dean did, he would never be able to be away from Dean for too long, and that the blond would join him in heaven.
And that's what kept them going, through all the shit the apocalypse had put them through so far. Because they knew they would make it. Because they were made for each other - Hell, Cas made Dean, at one point - and they had forever to be together.