It's not that he wants to, when he presses the sarky historian against the wall, their bodies flush against each other as his teeth scrape the pale skin of the older man's neck. Because he can almost believe that the fire flooding his veins is just leftover adrenaline bleeding through the centuries from the animus.

And it's certainly not because he requires it; because it's not like his world would fall apart without him. At least that's what he tells himself in those rare nights where he's left to sleep alone whilst the other assassin pulls night shifts in the glow of his monitor, the cold metallic glare highlighting the dark circles that frame tired eyes beneath his frames.

And he tells himself that it's just the harsh radiance from the screen, the whirring of the machines and the rapid tapping of keys underneath Shaun's fingers that keep him awake… And it's certainly not because he can't shake the thought that the fingers themselves are missing from where they should be, linked between his own.

It's just that every time he came crashing down to earth there was always someone there to pick up the pieces. The brittle, sarcastic man that acted like he hated him most of the time yet was always there for him when he was needed. It's because he can't shake the thought that whenever he emerges from the world of the past, when his consciousness fully reforms and he's left with the cold realisation of who he really is, the bitter taste of the truth of their hopeless situation sour in the back of his throat, Shaun is always there, fingers laced between his own. Solid and unmoving. Warm and true.

Nothing is true… He absentmindedly corrected himself as he ran calloused fingers along the stubble peppered curve of the historian's jawline, fingers dipping into the hollow behind his ear and curling there. Everything is permitted.

"What have you done to me?" He growled softly against pale skin, frustration bubbling in his stomach as it always did when he started overthinking their situation.

"Nothing… Yet." The historian murmured in reply as sultry brown eyes slowly opened, regarding the young assassin with a curious light smouldering in the dark irises. "What's got you so preoccupied tonight?"

Desmond pressed his thumb against the curve of Shaun's abused bottom lip, subconsciously biting down upon his own as he did so. His eyes slipped shut as he felt a wet muscle flick against his rough skin and he swallowed hard when Shaun parted his lips to bite down gently, his tongue soft against the pad of his thumb.

"You." Desmond murmured, his voice rough and heady as his eyes flicked open again. Removing his thumb he leaned forward to take Shaun's mouth in a bruising kiss, capturing his lips like a victory as he coaxed them apart with his tongue. Both men fought for dominance as they clashed.

"You've been thinking again haven't you?" Shaun raised an eyebrow and smirked without missing a beat as they parted for air. "Stupid." He mocked, his next words catching in his throat for a second as Desmond moved to bite down on his already bruised neck, his breath escaping in a panting moan that was both pain and pleasure. "Y-you know you hardly have the mental capacity for such things."

"Shut up." Desmond hissed, rolling his hips against Shaun's and smirking a little at the shudder that he felt pass through the historian's body and into his own as he pressed him more forcefully into the wall. He could already feel Shaun resisting the urge to thrust up against him, fingernails digging into the palms of his hands hard enough to draw blood. Their noses touched. "Just shut up for once."

"Make me." Came Shaun's breathless reply, a challenge.

Desmond's smirk grew wider as he forced a leg in between the historian's, slowly and deliberately rubbing his knee up against the cloth that covered his straining erection. He watched Shaun bite back a groan, his eyelids slipping shut against the sensation. Desmond took a moment to drink in the situation, savouring every moment of the historian's discomfort, of his arousal, of Shaun for once being so at his mercy. Then he leant forward, their lips meeting as he sank his teeth into Shaun's bottom lip, already swollen and broken from abuse. He grinned at the sound his actions drew from his lover, a soft noise half whimper, half groan: fully arousal.

He ran his hands along the hem of the sweater than Shaun always wore, even when it was too warm to justify doing so. 'So bloody British' Desmond mused as he pulled it roughly over his head, discarding it in a crumbled heap upon the ground. Shaun grumbled a little as he straightened his glasses, but all complaints promptly flew from his mind when that mouth returned to his neck. He felt thick fingers working the buttons at the top of his shirt and sighed softly as he let his head fall back against the wall.

Desmond made short work of his buttons, pulling his shirt open to expose his chest to the cold air. Shaun gasped softly as the assassins' thick mouth dropped to his chest, his tongue flicking across trembling skin as he caught a nipple between his teeth. He hissed as Desmond twisted softly, threading a hand through his hair and tugging roughly at the short dark strands. He felt Desmond grow low in his throat, the sound reverberating across his skin as that mouth worked him. Usually he was the one who took point on their physical encounters but this time Desmond was the one in control. He found that he didn't really mind that even as he lost his shirt, the rough stone of the wall grazing his back ever so slightly as he was pushed against it.

When Desmond's hands fumbled at his belt he moved his hands to help but they were slapped away. Ezio's descendent turned his dark eyes to him and he felt a bolt of arousal shoot through him at the barely contained lust held within those orbs. Desmond's hand slipped beneath his trousers, into his boxers, grasping him as he gasped. Those dark eyes never left his own as Desmond worked him, calloused hands running up and down his length, watching intently as pleasure flickered across his face. He brought their mouths together again as Shaun's hands clawed at the wall behind him, the whole word seeming to recede behind those hands and that mouth.

Desmond moaned into his mouth, the sound running straight to Shaun's crotch and suddenly he realised that his partner was wearing far too many clothes. Desmond obliged as Shaun grasped the zipper of his hoody, drawing it down and pushing it from his shoulders. His t-shirt followed and then Desmond's hands were upon him again, encouraging him to step out of his trousers and boxers, leaving them to pool around his ankles on the floor. Shaun kicked them away as he reached for the fastenings on Desmond's jeans, tugging them open with a sudden need. Desmond grasped his wrists as he fumbled, pushing them hard against the wall, holding him there as he moved lips and teeth against his neck.

"Fuck." Shaun hissed through his teeth as Desmond pressed the length of his body against him, their bare skin meeting with a thrumming heat.

"If you insist." Desmond all but groaned in Shaun's ear as he released his wrists, sliding his hands down to grasp his rear, strong fingers gripping and kneading at the hard flesh he found there. Desmond was still wearing his trousers but somehow that didn't seem to matter right then as he ground their hips together, Shaun biting back a strangled moan as rough denim rubbed against him.

Shaun's back arched up off the wall as he felt a thick finger slip inside of him, the slight pressure slightly uncomfortable but by no means unwelcome.

"Desmond…" He groaned his name as another finger joined the first and stretched his tight skin. Desmond growled headily in his ear as he scissored him open and Shaun whimpered, gritting his back teeth as his crotch swelled.

"I like having you like this," Desmond purred as he ran his tongue along the curve of Shaun's earlobe. "All tight and practically begging me to take you."

"Well get a fucking move on then." Shaun snapped, unable to take the slow pace nor the pleading noises the other man was drawing from him.

"So demanding." Desmond breathed heavily against his skin as he withdrew his fingers.

With one swift movement he unbuttoned his own jeans and stepped out of them. In the back of Shaun's mind he noted that the assassin seemed to have been going commando today. But all coherent thoughts were swiftly going out of his head as Desmond spun him round, running his hands up his inner thighs and making his skin quiver. He pressed the historian hard against the brick as his fingers worked a way inside of him again, almost painful in the tight heat. Shaun bit his lip, turning his face into the wall, his glasses shifting to one side and sitting skew upon the bridge of his nose as he struggled with his breathing.

And then breathing became all but impossible as he felt something much thicker than fingers press against his entrance.

"Tell me how bad you want this."

Shaun growled in frustration, trying to look threatening as he looked back over his shoulder at the smirking assassin.

"Miles, I swear to Juno if you don't get a fucking move on I'll – "

Whatever it was that Shaun was threatening to do to him was lost in a strangled cry as the assassin sheathed himself fully in his tight heat, pressing him hard against the wall as he hit that spot inside of him which made him see stars in one swift movement.

"What was that?" Desmond panted against his ear.

"Argh, fuck." Shaun spat as he clawed the wall, all coherent though flying from his mind as Desmond slammed into him, filling him with a painful warmth.

"If you insist." He purred as he started to move, not giving Shaun a moment to catch his breath.

Shaun inhaled harshly as he steadied himself against the wall, the rough brick scraping against the heel of his hand as he was pressed hard against it.

Shaun's shirt hung from his shoulders, cloth swaying against his body as he was moved. Desmond bit down upon his ear lobe, a slick tongue flicking into the hollow of his ear and Shaun struggled not to moan as the assassin's hands moved achingly slowly across his chest. Rough fingertips found his nipples and glided across them, pulling him back against his chest, flicking and laughing at the strangled noises Shaun made in response.

"Fuck. Desmond." Shaun moaned his partner's name through his teeth as Desmond bit down harshly on his neck, dragging his teeth all the way back up to worry his ear again. The assassin growled softly in response, pulling out nearly all the way before thrusting back in hard. Before Shaun could even catch a breath Desmond was pulling out and pushing in again, colliding with that spot inside of him that sent fire coursing through his veins.

Shaun's eyes practically rolled back in his head when Desmond slid his hand round to slide along his straining member, clever fingers working him up and down with a slick heat. He choked on his own cry as pleasure burst through his body, sparking out from the roots of his very being. The feeling of Desmond's rough hand against his sensitive skin was too much as he stroked him, his hard body warm and throbbing against his back as their bodies were pulled together. He came hard, so wound from everything that had come before and Desmond sank his teeth into the crook of his shoulder as he spilled himself over his hand. He didn't let up even for a second as he felt the historian tighten around him, only needing a few more harsh strokes to ride out his own end.

He felt Shaun grimace slightly as the soft burn filled his insides and smirked slightly knowing that he had once again marked the proud man as his own.

He pulled out with a strangled noise as they sank to the floor together, bodies still intertwined, exposed knees scraping against the stone their skin found there. Disentangling himself slightly, Desmond pulled Shaun down onto his back, leaning over him and collapsing onto him with a heavy sigh. Shaun grunted softly as Desmond curled into him, savouring the frantic fluttering of his heart against his ear where he rested his head upon his heaving chest.

"What was that about?" Shaun breathed heavily, attempting to slide his flippant mask back into place even as he curled his arm around Desmond in a gesture that was becoming a little too familiar to both of them.

"You know." Desmond pulled back a little regard him, head cocked, a familiar pouting expression upon his face.

Shaun looked up at him, a curious expression burning in his dark eyes as he slid his hand up to cup the curve of the assassin's cheek. Desmond leaned into the touch with a soft sigh and there was a sudden electric sensation thrumming against Shaun's hand where their skin met.

"I think I'm starting to." He murmured softly and was surprised by the reaction that fluttered across Desmond's face, like a sudden realisation setting in that had been boiling just below the surface all this time. He was surprised to recognise a similar sensation settling in the pit of his own stomach. Warm and unexpected, but not unpleasant by any means.

Then Desmond's lips were moving against his own again and it was suddenly very difficult to focus on anything else.

No, the assassin thought as he sighed into Shaun's mouth. It's certainly not because he wants to, every time he finds comfort in the embrace of the historian within whose hands he was unravelling a little more each day.

But it might just be because he needs to.