A/N: I wrote this little oneshot for a comment fest on LJ. It was so much fun writing Merlin and Arthur again, it's been far too long!

It was a rare treat for Merlin to get an evening to himself, so he decided to put it to good use.

Arthur was at the library doing some research for an essay. He'd mentioned going for a drink with his rugby mates afterwards, so Merlin wasn't expecting him back till late. He could take his time for once instead of frantically trying to get himself off while Arthur was taking his morning shower.

Merlin knew that his way of masturbating was unconventional, but it was just how he'd always done it-from long before he was old enough to actually ejaculate-and it worked for him. He only realised that most boys did it differently when he was in his early teens. The wrist jerking gesture that was bandied about when wanking came up in conversation genuinely confused Merlin for a while. But a little internet research when his mum was out one day proved to be very enlightening-in more ways than one. Merlin also discovered that he was much more turned on by images of men wanking than by ones of naked women, so that was another suspicion confirmed. He was gay and he wanked in a weird way, but he was okay with both of those facts and mostly carried on doing what he'd always done.

So, with Arthur out and their shared room all to himself, Merlin stripped down to his boxers and settled down on his bed with his laptop open and started scrolling through his Tumblr feed.

At first he just looked at the pictures and gifs, enjoying the sensation of his prick swelling and thickening in the confines of his underwear. Then he came across a short video and clicked on the link. "Fuck," he muttered, pressing against his cock with the heel of his hand and rubbing slowly. One of the guys looked like a twinkier version of Arthur. He was slimmer and more delicate, but the shaggy blond hair and aristocratic profile were very similar. Merlin felt dirty watching it. He normally tried very hard not to think about Arthur when he was doing this, but he couldn't bring himself to stop watching. The boys on the screen were sucking each other's dicks. The filthy slurping sounds and hums of enthusiastic pleasure sent a hot rush of arousal through Merlin. He increased the pressure on his erection, rubbing hard through the fabric and he felt the sticky catch of wetness at the tip.

The scene cut and the Arthur lookalike was being fucked now, moaning and arching as the darker man thrust into him with relentless intensity. Merlin couldn't wait anymore. He slammed his laptop shut and shoved it onto the floor beside his bed. He wriggled quickly out of his underwear and pulled his duvet aside. Turning onto his belly, he reached for his discarded T-shirt and spread it out on the mattress beneath him. He pressed his cock hard against the mattress, desperate for the friction that it provided and started to rock his hips, heavy pressure on the base of his cock as he ground himself down. He let his head fall into his pillow, stifling his moans as he gave himself up to the feeling, hot pleasure rising from the ache in his balls. His eyes were closed, breath coming in gasps as his mind flickered with the image of the blond man in the video-only broader, more muscular, more Arthur .

Lost in the rising tide of sensation, Merlin must have missed the sound of the door opening. Because it was the sound of Arthur's voice that shocked him into stillness, as effective as a bucket of icy water.

"Merlin-what the bloody hell are you doing?" He sounded a strange blend of irritated and confused.

Heart hammering and face flaming with mortification, Merlin rolled over to face him. He took the T-shirt with him, clutching it over his wilting erection like a shield as he lay on his back looking up at Arthur. "Um..." he tried, but words failed him.

Luckily Arthur didn't seem to have the same problem, because this situation was bad enough without the addition of awkward silences. "Well, obviously I get that you're... well... getting off ." Arthur gestured in a slightly flaily way towards Merlin's crotch. "But really, like that? Is that how you always do it, Merlin? Doesn't it hurt?" He frowned, genuine concern crossing his handsome face for a moment.

"Yes." The word caught in Merlin's throat, his mouth dry. "I mean, yes. That's how I always do it. And no, it doesn't hurt-obviously-otherwise I wouldn't do it, would I?" A little acid crept into his tone. He wasn't completely stupid.

"But it can't be good for you." Arthur persisted. "I'm sure I read something once somewhere about it on the internet. It makes you less sensitive if you do it that way all the time."

"Well thank you for your concern." Merlin glared now, wishing he'd just fuck off. Wasn't there some unspoken roommate code that should be at work here? If you catch someone having a wank you should bloody well leave them to it and let them finish. "But my penis is perfectly sensitive and in good working order. I'm just like doing it this way, okay?"

"It's just so typical of you, Merlin." Arthur shook his head. "Honestly, how can you get to be nineteen years old and not even know how to wank properly?"

"Well I don't know about your school, but it wasn't something we covered in sex education classes at mine." Merlin was angry now. His alone time was ruined, his balls were aching and he'd lost his erection. Even if Arthur did bugger off now, he'd pretty much totally ruined the moment. Merlin's voice rose as he continued, glaring at Arthur and his stupid perfect hair and gorgeous arrogant face. "If you're such a sodding expert at the ancient art of masturbation, why don't you just whip it out right now and show me how it's done? It's a shame to let all that expertise go to waste."

Arthur glared back at Merlin, a delicate flush of angry pink painting his cheekbones as his blue eyes flashed. The room was silent for a moment as their gazes locked and held.

"All right then." Arthur squared his shoulders and strode across the room. "Budge up."

Merlin scrambled to sit sideways on his bed, heart hammering out a crazy tattoo against his ribs as Arthur toed out of his shoes and shrugged off his jacket. Okay, so Arthur was actually going to do this. Fucking hell . Merlin had never thought for a moment that Arthur would take him seriously; but then Arthur had never been one to back down from a challenge. Merlin's eyes dropped to Arthur's crotch as he unfastened his jeans and pushed them down, and he was interested to note that Arthur was already hard. Merlin hadn't been expecting that. His own traumatised prick perked up again at the sight of the tent in Arthur's boxers. Maybe this evening wasn't going to be a total failure after all.

Arthur went to lower himself down to sit beside Merlin, but Merlin stopped him. "Aren't you still a little overdressed?" He raised his eyebrows pointedly, his gaze swooping over Arthur's T-shirt and underwear. "That's hardly fair. Anyway, you'll only get spunk all over yourself if you don't strip." Merlin was nothing if not practical.

" You were about to jizz all over your bed, Merlin," Arthur pointed out. "And that's another reason that my way is better; the mess is easier to deal with."

Smug git, Merlin thought. But any half formed retorts were lost en route from his brain to his mouth as Arthur stripped off his T-shirt and divested himself of his boxers. Of course, Merlin had seen Arthur naked occasionally-they'd shared a room for over six months now-but he'd never seen Arthur hard before. His thick, flushed cock bobbed as he stepped out of his underwear, and swayed deliciously as he advanced on Merlin.

When he sat beside Merlin on the bed, their legs touched. Merlin's brain nearly short-circuited at the feeling of warm skin and the catch of blond hairs on dark as Arthur shifted and made himself comfortable. Arthur took his cock in hand and just held it for a moment, not moving, gripping it loosely.

"Well, come on then." He sounded impatient, the usual irritation very present. His blue gaze dropped from Merlin's eyes to the crumpled T-shirt in his lap and back up. "Show me what we're working with and we can get started."

Merlin felt heat sweep over his face and neck. But the thought of Arthur looking at his cock ignited a flare of want deep inside him, so he pushed the T-shirt aside and displayed himself to Arthur's inspection. Merlin was fully hard again; the dirty-squirmy-shame of this whole situation was apparently something that really did it for him-who knew? He put his hands on his thighs, resisting the urge to touch his erection and looked down at himself. His prick was very different to Arthur's, longer but slimmer. The skin was pale at the base, blue-purple veins showing through the skin, but it was flushed pink up towards the head and where his glans peeked through his foreskin it was a rich red colour, shiny and wet.

"Okay." Arthur sounded a little hoarse and his hand moved on his own cock at last, squeezing and sliding. "Do it like this, Merlin." Merlin watched as Arthur's foreskin rolled right back, revealing the perfect crown, pink and glistening. Merlin's mouth watered.

Merlin copied the movement of Arthur's hand. It was good, but not what he was used to. Of course he had tried it like this before on occasion, but it always felt too light, too teasing compared to his method. He missed the weight of his body and the pressure on his cock and if he managed to come like this it always took him ages. He took a shaky breath and moved his hand faster. As he watched Arthur's hand moving and listened to the brush of skin on skin Merlin's balls tightened and tingled. Somehow he didn't think that taking a long time to come was going to be a problem today.

"Pull your foreskin back more with each stroke," Arthur muttered, a little breathless now. "It feels really good when it rolls up and down."

Merlin tried, but his was tighter than Arthur's and didn't move as easily. He hissed as he took it a little too far. "Mine doesn't stretch as well as yours."

"Mine's had more practice. Keep jerking off like this every day for a couple of weeks and yours will get used to it." A bead of fluid swelled out of the tip of Arthur's cock and he thumbed across the head, smearing it down his shaft. "Touch your balls too, like this." Arthur cupped his sack with his hand, running his palm over the blond fuzz then gripping and tugging gently. Merlin wondered how Arthur's wrinkled sac would feel against his cheek, how rich the scent of Arthur would be if he could bury his face there and breathe in. His own balls tightened further and a small whimper escaped as he copied Arthur, rubbing them between his fingers and teasing the silky skin behind as his hand stroked his cock harder and faster.

"Is that good Merlin? It looks good. It looks so much better than what you were doing before." Arthur's hand moved faster. "Your poor cock deserves better than being rubbed off against bed sheets and dirty laundry."

"Yes." Pleasure curled hot and bright in Merlin's belly and he moaned. "Yes, it's good."

"I told you so." Arthur's hand was a blur now. "Are you going to come? Go on, Merlin. Do it."

And Merlin did. He gave himself up to the sensations sweeping through him. He felt the shiver-pulse of his cock in his hand and the deep beat and clench inside as he spurted hard, striping his chest as his body arched helplessly.

"Fuck, Merlin!" Arthur sounded shocked as he joined him, coming with Merlin's name on his lips as come spilled over his fist and dribbled over his fingers as he worked himself through it. His leg jerked and pressed against Merlin's. Merlin watched as Arthur's face went slack with pleasure, his flushed lips parting and Merlin wanted to kiss Arthur so badly it hurt.

They sprawled side-by-side; breathing slowing, pricks softening as their come cooled on their skin, and the silence stretched out between them.

"Well... um... thanks. I guess." Merlin caved first. He chanced a glance at Arthur, who lay boneless and come-drunk beside him, his eyes closed.

"You're welcome." Arthur's eyes half-opened and a flash of teasing blue fixed on Merlin. "We can practise again another day if you want some more pointers?" Merlin's jaw dropped as his mind scrabbled around, trying to make sense of what Arthur was offering. "Or maybe..." Arthur continued, his voice determinedly casual. "We could do it to each other next time?"

Merlin grinned, and a sudden surge of boldness seized him. He leaned over, closing the gap between them and pressed his lips against Arthur's. "Okay," he whispered against Arthur's mouth. "I'd like that." A strong hand on the back of Merlin's neck stopped him from moving away, and Arthur's lips parted against Merlin's like a promise.

A/N: Thank you for reading!