Cas keeps himself hidden. He has for weeks, but he’s always watching, ensuring that no Leviathan catches up with Dean. He watches as Dean lets his vampire companion partially undress his, take his cock inside his mouth, make him come.
Cas has seen many acts of sex, variations, positions, many different partners and species. He’s even seen Dean have sex, not that he makes a habit of it, but, on occasion, he’s attempted to check in at inopportune times.
But Cas has never seen Dean have sex with a man.
It’s rough and it’s hard. Dean’s smiling, almost laughing as he reaches up and back to grab Benny’s head, to pull him in closer. Cas can hear them clear as crystal, grunting and huffing. Dean’s swearing as he rears back
“Fuck, yes,” he whispers. Cas can only assume that Dean doesn’t want to alert any beings within earshot of their location. Cas vows to watch the perimeter. He can do both – watch for encroachers and watch Dean and Benny.
“Don’t fucking stop,” Dean groans, yanking at the back of Benny’s neck, twisting his fingers in his hair.
Cas feels his vessel respond. He feels his own cock grow hard and stand at attention. He instinctually grips himself over his dress pants as he watches Benny grip Dean’s bare hips with meaty hands, a bruising grip.
Benny breathes heavily, braces his head between Dean’s shoulder blades. He nuzzles the leather, sniffs. “Gotta stop sometime, Dean,” he answers. “But want you to come again. You gonna come again?”
“Oh, yeah,” Dean replies. “That’s happening.” He breathes and hangs his head, takes what Benny gives him.
Benny runs a hand up under the layers of clothing covering Dean’s torso, and Dean moans.
“Fuck – use your nails,” Dean says, bucking back into Benny. “Hard.”
Benny laughs and does what he’s told, making Dean his and throw his head up, arch his neck. Cas sees the teeth as they descend, see Benny close his eyes and mouth and shake his head, slamming into the man under him harder on each thrust.
Cas knows he doesn’t need to intervene; he’s seen what this vampire has done for Dean before and just now. So, he keeps watching, unzips his pants, grips himself in his hand – just as Dean grips his own cock – and thrusts in time.
He watches, pacing with them. After three more hard pushes from Benny, the men on the other side of the stream amongst the brush and boulders, growl their blissful release.
As they collapse, Cas finishes quietly then tucks himself away. He sinks further into his hiding place and scans the perimeter once more as Dean and Benny regain their bearings, redressing, laughing and groaning in ways that Cas can only describe as satisfied.