Merlin looks up from his books in surprise when Arthur finds him at a study cubicle in the back corner of the library.
"C'mon, let's get out of here," Arthur says, nudging Merlin with his leg.
"I can't. I have an exam tomorrow and I really need to go over this again."
"You always say that, but then you always get top marks," Arthur grumbles.
Merlin rolls his eyes. "I get top marks because I study."
"You can study later." Arthur nudges him again, harder this time.
"I'm not leaving this library, Arthur," Merlin says, resolutely crossing his arms and leaning back in his chair.
Arthur gets that familiar glint in his eye — the one Merlin knows means trouble, and before he even realises what's happening, Arthur has Merlin out of his chair with his back to the desk. "You are so pushy," he says, but lets Arthur manoeuvre him up so he's sitting on the desk
"And you love it," Arthur answers with a smirk as he sits down in the chair Merlin was just occupying.
"Arthur," Merlin hisses as Arthur pulls the chair so he's sitting right between Merlin's legs, "you do realise we are not the only people in this library?"
Arthur shrugs before attacking the button on Merlin's jeans. "I tried to get you to leave, but you insisted on staying put. They way I see it, you have only yourself to blame here."
Merlin's protest dies on his lips when Arthur pulls his cock out and strokes it from base to tip, his thumb flicking over the head.
"Now remember, people are studying, so try to keep it down," Arthur says with mock seriousness before leaning in and licking the head of Merlin's cock.
"Oh shit," Merlin gasps and falls back onto his elbows, bumping his head on the back wall of the cubicle
Arthur is ridiculously good at sucking cock, and it's all Merlin can do not to let out a loud and embarrassing moan when Arthur swallows him down. Despite his best efforts not to make a sound, Merlin can't help the way his breaths come fast and ragged as the tight, slick heat of Arthur's mouth surrounds him. Arthur isn't doing much to stay quiet either the way he's slurping obscenely at Merlin's cock, all wet and filthy. A tiny part of Merlin's brain thinks he should be outraged, but when Arthur does that thing with his tongue, Merlin decides he's doesn't give a shit if the whole library knows Arthur is sucking him off.
Merlin grips the edge of the desk when his cock hits the back of Arthur's throat, and when Arthur swallows around it, taking him deeper, Merlin's hips buck up of their own accord. Arthur brings his hands up to Merlin's waist, holding him down without ever losing his rhythm.
"Oh god," Merlin gasps, "Arthur, I'm gonna come."
Arthur just makes an encouraging noise and takes him all the way down his throat until his chin bumps into Merlin's balls. Arthur has him pinned at the hips and Merlin can't move — he can't thrust up into Arthur's mouth, he can't cry out, he can't do anything except bite his lip and come down Arthur's throat.
Arthur pulls his mouth off Merlin's cock with a wet pop and grins up from between his legs. Merlin slumps back against the cubicle and does his best to glare, but it's really hard when his toes are still tingling. "You're a bastard," he says breathlessly.
"I think you mean, 'oh Arthur, you give the best blowjobs ever.'"
Merlin chuckles weakly and wraps his hand in Arthur's hair, tugging him up so he's leaning over Merlin. "You give the best blowjobs ever, but let's not forget how much you love sucking my cock," Merlin whispers when Arthur is close.
"Maybe," Arthur murmurs and then licks his way into Merlin's mouth, kissing him soundly.
Merlin can feel Arthur's erection digging into his hip through his jeans — it's unmistakable when Arthur thrusts against him.
"That's very subtle, Arthur, really," Merlin says when he breaks the kiss.
"I swear to god, if you say anything about having to study, that will be the last blowjob I ever give you."
"I'm not sucking you off here," Merlin says, glancing around as he zips himself back up. There is still no one in their row of cubicles, but he can hear hushed voices not too far away, and now that the glow from his orgasm is fading, he feels nervous again.
Arthur smirks and starts stuffing Merlin's books into his bag. "Then I guess we just have to leave, don't we?"
"You planned this, didn't you?" Merlin asks when Arthur slings Merlin's bag over his shoulder and grabs Merlin's hand, pulling him to his feet.
Arthur just grins and pushes Merlin toward the exit.