Chapter One

What did you say?

Tony Stark was not a sentimental man. Nor one to remember anniversaries or invitations - hell, he didn't even know his own social security number. So when Thor told him that Loki's birthday was in two days, Tony's immediate reaction was genuine surprise followed by a shrug of indifference.

"Will you be offering Loki your wishes, Man of Iron?" Thor asked him. At that, Tony raised an eyebrow. Had the others told Thor? Even though his on-and-off relationship (if they could even call it a relationship) with Loki was barely a secret anymore, the other Avengers had sworn - for the sake of Tony's continued existence - that they wouldn't tell Loki's muscular and incredibly powerful older brother.

"Why would I get Loki anything?" he answered sharply. He tried to avoid looking directly at Thor. For some inexplicable reason, Tony was feeling guilty. Maybe it was because Loki still ignored Thor's existence while favouring Tony with the occasional intel, or maybe it was because he was sleeping with the guy's brother - either way, the conversation was making him uneasy. And the thought of Loki's birthday coming up - shit, what could he possibly give Loki that the Norse god didn't already have?

Thor's chair made a soft screech on the dining room floor as he shifted his position, his big blue eyes locking onto Tony's. "If you were to present him with a gift," Thor continued in a light tone, "Might I suggest a bouquet of wonderful roses, or heart-shaped chocolates-"

"Oh g- who told you? Was it Steve? Did Steve tell you?" Tony groaned, running a hand through his hair. "It was Clint, wasn't it?"

Thor said nothing though his lips curved into a smile. So he wasn't going to tear him apart after all. That was a relief. Tony sighed before asking half-heartedly, "What does Loki like anyway? Aside from, you know," he paused, gesturing to the windows that gave way to the city skyline, his gaze lingering on the massive hole in a tall building that Loki had blasted through last year. He had no idea why the city hadn't fixed it yet.

He was sleeping with a psychopath. A destructive lunatic. For what seemed like the hundredth time that week, Tony's thoughts drifted to Loki and he found himself wondering what the hell he was doing, getting into bed with a dangerous enemy.

Out of the corner of his eye, Tony could see Thor surveying him with a mixture of curiosity and happiness. He held back a sigh, managing to avoid eye-contact while he continued rummaging about in the kitchen cupboards. Thor's approval was making Tony feel even worse.

"My brother has always had a fondness for horses," Thor finally replied.

"Like 'My Little Pony'?" He pulled out a wineglass from the cabinet.

"I have never set eyes on your pony."

"Would you like to?" Tony smirked, when -

BA-BOOM! The whole mansion shook with a thunderous noise.

Tony jerked backwards with a start, narrowly catching the wineglass slipping from his hand as Thor leapt to his feet. With a loud crack through the air, Mjolnir slammed into the palm of Thor's open hand while Tony began cursing, narrowly avoiding the broken glass as he made his way out of the kitchen.

"JARVIS, what the hell was that?" he demanded. Back in the dining area, Thor's head continued to swivel in every direction, his expression wary.

"I believe it came from Dr. Banner's room, sir," JARVIS replied. Thor and Tony exchanged looks, hurrying to the elevator. Whatever that noise was, it didn't sound good.

Dr. Banner wasn't in his room.

One missing scientist, five hours, and a wild goose chase later, The Avengers were tracking what they hoped was Banner's energy signature through an abandoned warehouse.

However, they weren't alone.

Loki looked up, hearing the sounds of hushed voices and hurried footsteps. He stepped back into the shadows, careful to remain invisible to them. The Avengers.

Captain America led the way. He appeared to be scolding the rest of the group. On his left, Barton seemed disinterested; on his right was Natasha, her face stoic, her movements cautious; Banner was absent; Thor looked frustrated, the air crackling around him; and Iron Man sauntered between Thor and Barton, uncharacteristically silent as the Captain continued to chastise them.

"We work together as a team, you don't take off in the middle of the night without warning and start blowing up half of the city-"

"Bruce was gone, Steve, something was obviously wrong and we couldn't just wait for the rest of you to come back," complained Tony. "We made the right call."

"You got caught in a trap and set off three bombs that endangered civilian life," Steve snapped. "And we still don't know where Bruce is."

"We have to find my brother," said Thor, sounding resigned. "Before it's too late."

"What does he have to do with this?" Barton piped up.

Good question, thought Loki, hidden in the shadows.

"For a start, he's been quiet for over five months now. We knew he was planning something really big, we just didn't know what." The Captain grimaced.

"And we recovered his staff in Dr. Banner's quarters," Thor added, a hint of anger in his voice.

Loki rolled his eyes. What sort of imbecile kidnaps his enemy and then leaves his signature weapon behind to be found by his enemies? It was offensive that The Avengers felt he was stupid enough to commit such a mistake. Or maybe they were too stupid to draw accurate conclusions from their own evidence. Anyone with eyes could see that he was being framed. Such fools, how were they even superheroes - Loki gasped, feeling a sudden pain in his abdomen. Clutching his stomach, he sucked in a lungful of air and exhaled slowly, his eyelids shut as he reminded himself to breathe.

When he next opened them, The Avengers had gone.

And Iron Man was standing in front of him.

"Stark." Loki said coolly, a natural smile on his lips. "Without your squabbling squad of superheroes. What a pleasure-"

"What the hell are you playing at?" Tony opened his helmet, dark eyes flashing. Before Loki could respond, he grabbed him by the collar and slammed the Asgardian into the wall. Loki winced.

"Where the hell is Bruce Banner?" he hissed. "You-"

"It wasn't me, Stark," Loki interrupted, sounding almost bored. "I have no idea who it was or why they have a replica of my staff."

"And I'm supposed to just believe you, am I?" Tony laughed bitterly. "Because you, Liesmith, are so trustworthy."

"I would not lie to you, Stark."

"Where is he?"

"My dearest Iron Man, you are as deaf as you are dumb. Now release me."

Tony's eyes burned with ferocity, as if he was trying to break into Loki's mind and crack the Asgardian's emotionless expression. He was furious, but a second emotion flickered behind the rage. A desire to believe Loki, to buy his words, that he really had nothing to do with what was happening - that Tony could trust him. But dammit of course he couldn't. Bruce was missing, maybe even dead. He was an idiot to think that there was more to Loki than the villain everyone aside from Thor always saw.

He thought that what they had - their fling or whatever it was - would prevent the Prankster from pulling his usual stunts. And, with the last eerily peaceful five months, Tony had begun harbouring a faint hope that Loki could even join them someday.

You're an idiot, Tony, he told himself, a complete idiot.

"If looks could kill, Stark," Loki commented wryly, wrenching Tony's attention back to the current situation.

"If you didn't take him then why are you here?"

Loki gave him an odd expression. "There was..." He hesitated. "I have...news...which may be of concern to you."

Tony's eyes narrowed, his grip loosening slightly. "Intel?"

"Release me first."

He opened his mouth to retort when Steve's voice filled his ear through the comms. "Tony! Where are you? We found Bruce, he's injured, not too badly, but we're gonna head back to headquarters - hello, can you hear me?"

"Loud and clear, Capsicle," Tony replied, a hint of annoyance in his voice. "Go on first, I'll be right there." His eyes were still on Loki, searching the armour, and his pale, indecipherable face, for any sign of guilt or maybe even a testament to the Prankster's innocence. He tilted his head to the side for a better view. Was it him or did Loki seem a lot paler - and did he gain weight?

"Picturing me naked again?" Loki's bright green eyes glinted with mischief. Or Lust. Tony choked, trying to ignore the burning desire in his chest. There was something intoxicating about Loki's presence. He wanted to lean further in, to meet Loki's soft lips - but no, he couldn't. For all he knew, Loki had done something horrible to Bruce.

Being with the Asgardian was like playing with explosives. Sooner or later, it would blow up in his face and The Avengers would be the ones to pay the price. Loki was too capricious, too dangerous, too much of a risk. Although he loved their breathless escapades and late night excitement, if things continued unchecked then Tony would become a liability to the team. Someone would get hurt - someone he cared about. All because he couldn't keep it in his pants. He needed to be able to kill Loki, especially if their long-time enemy was sneaking about the mansion and kidnapping the others.

"We have to stop." Tony stepped back, releasing him. Loki blinked twice in confusion, fingering his freed collar as he began slowly circling Tony where he stood. Keeping still, Tony watched the way Loki's body moved, feeling strangely aroused by the intensity of the Asgardian's gaze as he stared at Tony though breathtakingly green eyes.

A tiny part of him had always been fascinated with Loki, a fascination that grew and grew until it became something tangible - a lethal affair that set off every alarm bell in his mind. But Loki was hard to resist. The emerald eyes flashing above a killer's smirk, the way he flicked his cloak and rolled his eyes, the way he walked and talked, sauntering about like he owned the world, the curl of his mouth, the odd looks he sometimes gave Tony, the dip in his hips, and the taste of his-

"You're on S.H.I.E.L.D's most wanted list!" Tony exclaimed, startling Loki. He gestured to the horned helmet and the rest of Loki's Asgardian outfit. "You're a criminal! And I'm..." Throwing his arms open wide, he gave a little twirl in the Iron Man suit, "I'm one of the good guys, I'm Iron Man, okay? This shouldn't have happened. Iron Man does not get into bed with Loki Laufeyson."

Loki smiled. "All evidence to the contrary, Iron Man."

"And you talk like you're a hundred years old!"

"Do not be intimidated by my wisdom."

"You're a psychopath, you blow people up because you think it's fun. You tried to take over the world, you've tried to kill me a thousand times in the past, and my friends-"

"You pursued me first."

"Because you were trying to destroy the world!"

"Who said I was referring to that?"

"You and me, this can't happen."

"It already has."

"Then it won't happen again."

"Stark, are you still blaming me for what transpired today? It. Was. Not. Me. I am not responsible for Dr. Banner's disappearance," Loki repeated, irritation clear on his face. Tony closed his helmet - cutting Loki off mid-sentence.

"Stark." His name fell from Loki's lips like an anchor, the voice soft but hard. "Stop being a fool." Tony aimed a fist towards Loki's head. It was now or never. Loki was closing the distance between them, his expression darkening. "I am with ch-"

Iron Man's palm flayed open but before the weapon was even fired, Loki gasped, doubling over as he clutched his stomach, his knees hitting the ground with a thud.

"That wasn't me," Tony muttered in surprise. His arm fell back to his side as he spun around wildly. What on earth had attacked Loki? The Asgardian's breathing had become ragged, his head bent forward and a hand clasped over his mouth. Ignoring a sudden pang of guilt, Tony darted forward to help Loki up - only to meet a green-eyed gaze filled with loathing.

"If you intend to kill me then this is a perfect opportunity," Loki managed to hiss.

Tony faltered. He wasn't actually going to pull the trigger. Not yet, anyway. Their relationship was just confusing and reprehending Loki, who probably was responsible for Bruce going missing, seemed like a good idea less than a minute ago.

"Shut up." Tony grabbed Loki's arm - earning him a scowl but little resistance - and draped it over his shoulder. Bending down slightly, he tried to use his own body weight to pull Loki up. "Come on, the mansion's not too far away, we'll look at your wounds there."

"I have...no wounds...Stark," Loki insisted, trying to push himself away from Tony despite his words coming out in short gasps. He was struggling to stand but his face was an impassive mask, only his eyes showed the barest hint of pain.

"The others won't be happy," Tony continued, ignoring Loki's protests. "But I'll tell them you didn't have anything to do with what happened to Bruce."

He hardly believed the words coming from his own mouth.

"What's the worse they could do to me, right? They already know I'm - you know - canoodling with you."

"Canoodling." Loki rolled his eyes. "How touching...you'll actually vouch for me. And to think...only a moment ago, you were so eager to blast your unborn child into smithereens."

"Yeah well you're - my what?"

"Surprise."

"What did you say?"

"I will not repeat myself, Stark."

"You're joking. You're joking, right? Loki, this isn't funny. I don't know what kind of humour you have on Asgard but we don't joke about these kinds of things on earth-"

"You fool. Do I look like I'm joking?" Loki snapped at the floor, unable to straighten himself.

"You're a dude, how are you - no, you're not a dude, but you are a dude but but but-" Wincing, Loki collapsed into Tony - cutting off the mindless rambling.

"Loki!" Tony caught him and gingerly placed placed an arm around Loki's waist to better support his weight. He tried not to panic. Tony Stark did not freak out. Freaking out never helped anyone. Besides, Loki couldn't really be - could he? It was impossible - wasn't it?

Then again, he was alien after all.

Their midnight meetings were proof enough that Loki's anatomy was different from ordinary humans. He could form the right parts but Tony had always assumed that those parts were just for show - he never once thought they were an actual part of Loki's real reproductive system. To be fair, he had never even thought about Loki's reproductive system. Who thought about those things anyway? And weren't there biological rules, pre-zygotic barriers, that clearly stated that different species couldn't interbreed? Loki couldn't be-

Tony sucked in a lungful of air. For the second time that day, he wondered what the hell he was doing. Why did he have to get into bed with a dangerous enemy?

From the side of Tony's neck, came a pained voice, "You should have never put it in."