Sam has no idea how to go about asking Castiel. No matter what he does to soften the moment, it's going to be awkward as fuck. There's no getting around it.
His opportunity comes when Dean goes out to get them dinner and leaves his brother and his angel alone in the motel room to research. The silence isn't uncomfortable beyond that Sam is getting redder and redder thinking about what he's about to ask. He shifts uncomfortably in his chair and fiddles with the pencil in his fingers. He opens his mouth to speak, closes it, opens in again and then loses his nerve.
Just as he's working up the courage for what seems like the 12th time, he's cut off with a sigh (something all too human that makes Sam wonder how much of Dean is rubbing off on the angel) from Castiel.
"Sam, there's obviously something you want to ask me. You've been fidgeting for the last 20 minutes and it's starting to get on even my nerves, and angels are somewhat known for patience."
It takes another five minutes of Sam squirming under the angel's stare and serious consideration of how Dean manages to have Cas looking at him this intensely all the time, before the hunter manages to ask his question.
It actually takes the celestial being by surprise, which, if he wasn't so goddamn embarrassed, Sam might be proud of. But as of this precise moment, he's more considering killing himself just so he doesn't have to be under Castiel's questioning gaze.
Sam doesn't know how long they sit there, but the room is getting hot as Cas studies him.
"You know what, forget it, man. It's no big deal. Let's pretend—"
Castiel holds up a hand, effectively silencing the hunter. "Take a deep breath, Sam." Something like amusement shines in the angel's blue eyes and Sam swears he sees the corner of Castiel's mouth twitch up. He pulls a piece of paper toward him and starts to jot down symbols and their matching pronunciations. "Here, these are what you're looking for."
Sam arches up against Gabriel, his hands pinned above his head by the angel's grace, which is starting to become a seriously fetish for the hunter. He gasps out a breath as his angel started to thrust into him slowly, carefully.
Gabe runs his fingers down Sam's sides, stopping to pinch lightly at a nipple and earning a sharp intake of air from the human. He settles his hands on Sam's hips, lifting slightly to get a better angle.
The hunter throws his head back and whimpers out, "More" but it's not in English and Gabriel falters, slows his hips and stares down at his human. His grace releases unconsciously and Sam's hands are reaching for the angel's chest, looking for purchase somewhere, anywhere.
"What—"
"[More]—please—I—" Sam grabs the archangel's bicep and pulls. Gabriel is still startled and falls forward easily onto the larger man's chest. They aren't so much kissing as breathing each other's air so when Sam speaks again, the angel feels it against his lips.
"Gabriel [harder], please—"
Gabe's never been one to disappoint.
He pulls out almost all the way before slamming back in, punching the breath right out of Sam. He repeats the motion, pushing back in so hard that the headboard crashes against the wall. He's never been this rough, this forceful, always careful of Sam's fragile human body. He doesn't ever want to hurt his human again so he keeps his power fully checked at all times. But this—words uttered in the language of the angels, the language of his family and he's lost all that reserve so carefully built. Gabriel doesn't know where Sam learned it and he never expected that this is what the hunter wanted.
Gabriel wraps his hands under Sam's shoulders using them to pull the man into each and every thrust. He feels the other man's body shaking, coming undone and it's the best feeling he's experienced, heaven or earth.
Sam's digging blunt fingernails into Gabe's shoulder blades, his long legs wrapping around the angel's calves. "Ga-Gabriel, [faster], oh shit, [faster], please—"
"Sammy—oh fuck," Gabriel piston's his hips faster, the bed sounds like it's going to hammer it's way through the wall. His stomach brushes against the hunter's dick, already leaking and twitching with each frenzied thrust and that's the end for Sam. His body goes taught and his back bows beautifully off the bed as he comes between them.
"[FUCK], Gabriel, oh [fuck]. I—oh shit. Fucking, don'tstopplease. [YES]!"
If the hunter's body clamping down on Gabe's cock for some reason wasn't enough, the way the words rolled off Sam's tongue, moaned into the archangel's ear surely pushed him over the edge. He bit down on the juncture of Sam's neck and shoulder hard enough to break the skin and taste the metallic tang of blood on his tongue.
Gabriel detached his mouth from Sam's skin only to be pulled into a sloppy, lazy kiss. He heaved a contented sigh into the hunter's mouth and felt the larger man chuckle.
"Wha's so funny," the angel slurred as he withdrew from Sam's body to settle next to him.
Sam grinned. "Nothing. I take it you enjoyed yourself?"
"Enjoyed myself? Sammy, I might not be abled to think straight for the rest of the week." Gabriel pinched at the human's side, earning a sharp intake of breath another laugh.
"And where the hell did you learn Enochian?"
Sam just blushed and tried to lean in and kiss the angel, an obvious avoidance.
Gabriel grinned suddenly as he put two and two together. "HOLY CRAP. YOU ASKED CASTIEL DIDN'T YOU?" Sam hid his face in his hands. "Oh man, how fucking awkward was that? I wonder if he told Dean."
Sam groaned audibly at that.
"Well if he didn't, I'm totally going to."
"GABRIEL!"