It's not until Arthur drops to his knees, yanking apart Merlin's belt that the full, undeniable weight of what was happening sets in.
Merlin can feel a pleasant tingling starting at his toes when Arthur pulls Merlin's cock from out of his pants, breathing hotly against the tip. He doesn't know how a pub crawl to stumbling into Gwaine's dodgy flat morphs into Arthur's lips sloppy on his cock — but Merlin has also been led to believe that you should never question a good thing.
He can see Gwaine's hands trail up Arthur's back, petting, wrinkling up his jumper.
Good and strong hands — hands that loved squeezing Merlin's shoulder comfortingly or keeping him upright while he's tankered. Gwaine has always been his biggest source of strength about everything in Merlin's life. "He's good at that, yeah?" Gwaine's voice sounds a couple octaves deeper than normal.
Merlin can only manage a head-nod before he gasps, digging his fingers into Arthur's blond hair.
Arthur moans and sucks his cock loudly, creating pressure and suction. Merlin bangs his own head against the wall, biting on his lower lip, trying to not come right there.
To distract him, Gwaine bends over Arthur, grabbing Merlin's face. He loves kissing Gwaine. His mouth tastes like sour apple candy and his tongue peels apart Merlin's willing lips. Gwaine kisses like he means to fuck you right then and right now, and it burns up a small inferno inside Merlin's belly.
The way Gwaine ruts against Gwaine's clothed arse, rocking him forward periodically and taking Merlin deeper down his throat… until he can feel ever muscle in Arthur's throat quivering… it's magnificent. Gwaine remains attached to Merlin's opening lips, muttering soft words and encouragements, but Merlin's not so sure it's entirely for him.
He's so caught up in the delirious moment before Merlin realises his reddened, painfully hard cock has been abandoned to the cool, empty air.
Arthur's lips join to trace over Merlin's cheek. He whispers Merlin's name, too quiet, too tender, and far too slow, nipping with teeth under his chin.
Someone's hand wraps around Merlin's prick, slicking the precum and Arthur's drool up its shaft. It's Arthur's mouth pushing against his this time. It's a lack of scratchy facial hair and Merlin can very much taste cock — his own cock on Arthur's tongue working past Merlin's teeth, sliding against his palate.
It's the kind of breathless, messy kiss that shoots white-hot constellations behind Merlin's eyelids.
Gwaine moans somewhere off to the side, mumbling and cursing at Arthur and Merlin swears he feels the reverberation of a chuckle. "You're such a tit," Gwaine mutters, jerking Merlin off quicker.
"No more than you are," Arthur replies, each syllable brushing to the raw-swollen surface of Merlin's lips. He wants to knock both of their skulls together, even at the risk of Gwaine's hand yanking too hard on him.
(Could they at least focus?)
With a whining noise, Merlin tightens his arm around Arthur and bites down sharply on Arthur's lip. The obvious, stuttering inhale is worth it.
"You little," Arthur breathes, ignoring Gwaine's laugh at the offended look.
Merlin's hips cant up into Gwaine's warm hand, leaving him pleading in whispers before Arthur grinds against his hip. Arthur's hand dips down right under his clothes to stroke and cup Merlin's bollocks. The feeling of Arthur's prick thickening in his jeans helps set him off, nearly in an instant with the combined sensations.
He cries out low against Arthur's neck, spending against both Arthur's and Gwaine's hand. Merlin breathes hard into hot, sweaty skin, and listens to his mates' approving groans. Gwaine's free hand sets against Merlin's nape, gently massaging.
"Best decision I've made tonight," he announces, and Merlin lifts his head, smiling at him.
It's the best he's made as well, but Merlin isn't going to inflate Arthur's ego much more already by admitting to that.
BBC Merlin is not mine. So back in 2013 I think? I wrote this in someone's Tumblr askbox and now I figured I'd get it actually published! xD Hope you enjoyed!