After Loki returned from Asgard it was determined that he should spend 2 years with the Avengers where he could be held responsible for his crimes on Midgard and they could make him atone for his crimes.
He had been at a low and longed for death when he ended up on Stark's floor of the tower and found him in a similar predicament. Drinking himself into oblivion to forget the actions of his past. The God of Mischief sat with the man but could not bring himself to play any tricks on the lost soul next to him.
As Tony drank he became more and more loose tongued, opening up to Loki without ever meaning to, making him end the night with the request that Loki stay with him that night, they didn't do anything other than sleep in one another's arms, providing comfort to the other. Tony awoke and remembered all that he confessed to the night before but couldn't bring himself to care for telling his enemy his weaknesses.
When the God awoke he looked down to see the other man curled up into him, watching Loki intently and all he could do was gaze back. It wasn't until that morning when the alcohol cleared his mind that he realised that Loki's arms were covered in red, raw cuts and scratches.
"Shit Loki, did you find a savage beast or something?" Loki looked at his arms and thought about the truth in Tony's words, they were indeed caused by a beast but what the man didn't know was that the beast was within.
"You could say that."
"Why didn't you say anything to any of us Lokes? We could have helped."
"Why would I inform any of you? As far as I can recall I am your prisoner. Why would I wish to let any of my captors know of my depravity? Of how much I hate myself? Of the 'savage beast' within me?" Tony had known that Loki wasn't the same as when he tried to take over the world but he had always assumed it was a result of his punishment, not something such as depression.
He couldn't stop himself from wrapping the God up in his arms even if he had wanted to. Tony pulled the broken man into his chest and held him tight. "Oh Loki." He pressed a chaste kiss into the man's long, raven hair and felt as the other relax, listening to the thrum of Tony's heartbeat and the steady hum of the arc reactor.
"Your heart Stark, it hums?" Tony chuckled at Loki's comment realising that he would not have known about his little predicament, and at the memory of Loki trying to control him but not understanding why he couldn't.
Tony lifted his undershirt up so that Loki was able to see the blue light emanating from his chest. He flinched slightly when Loki tentatively reached towards it but relaxed when the man began tracing the scars around it, looking on in curiousity.
"Not all Midgards have these, what is it?"
"It's a battery."
"For your suit? Why wouldn't it be built into the metal rather than you though?"
"Not for the suit. For my heart. Without this I would be dead in a matter of minutes." At these words Loki looked almost scared to touch Tony in case he accidently did something to hurt the man he had ended up on top of. "It's alright Lo, unless you pull it out you won't hurt me." Loki looked up as if assessing the truth in the man's face before deeming him to not be lying so Loki began tracing the patterned scars once more before placing a kiss to the centre of the reactor.
He looked up when he heard the man above sniffing and saw a tear roll slowly down the man's stubbled chin so he pulled away completely. Until Tony protested anyway. "Come back."
"I made you cry Stark. I'm sorry. Tell me what to do and I shall fix it." Tony gave a small smile at these words and repeated the same two words, "come back."
"But Stark-"
"Loki I'm fine, it's just that most people don't, well they don't- people are freaked out by the arc reactor, that's what it's called. Most people don't run on battery Lo, just me. You seem fascinated by it. I was just shocked, yet rejoiced, when you didn't act like I was a freak of nature. Thank you."
Loki watched the man as he spoke before slowly resuming his previous position on Stark. "Most people are idiots then," he said before placing a kiss on the arc reactor once more. "That device there keeps you alive, that is amazing. You could never be a freak of nature. I was fascinated as that little thing keeps you alive, what's not to be amazed by?" With this he reached his head up and placed a chaste kiss against the corner of Tony's mouth. "You aren't the freak of nature in this room Stark."
Tony looked to Loki in confusion at his words, confusion which only deepens when Loki moves to stand at the end of the bed, away from Tony. Loki looks at the man one last time before closing his eyes and showing Tony his true skin, azure and crimson. Tony gasps when he sees Loki begin to change how he looked but not in fear, in wonder.
"Look upon the savage beast within Stark." He expected to be greeted with disgust from the mechanic, what he was not expecting was to feel Tony's hand running over his ice cold skin, burning him with every touch, every blazing trail across his skin. When he felt this though his eyes shot open wide and was shocked by the side of Tony kneeling on the end of the bed, faces inches apart and eyes locked with one another.
"Oh my God, Loki." The frost giant waited for the disgust to show in the man's voice, and actions, but it never appeared. "You're freezing. You're glacial. You're gorgeous." With that last sentence Tony closed the gap between them and sealed their lips together. Loki changed back to his normal skin without breaking the kiss, the sudden change in the temperature of the body against him caused Tony to pull back sharply, only to gaze at the man with half-lidded eyes.
Tony did nothing but look at the man so Loki decided to take matters into his own hand and this time he initiated the kiss, opening his mouth to the mechanic which Tony promptly took advantage of by slipping his tongue into Loki's waiting mouth.
After that day the two of them spent much of their time together, relishing in the comfort of one another rather than their bottles or blades. That is until one day, when they fought, when Loki decided that he couldn't keep acting as though Tony would one day feel for him as he did for Tony.
They both said horrible things to one another that day, using things that they had been told in confidence against the other. That night Loki regretted his words, he had to be with Tony even if the man could never love him back, he ran down to the lab and hit the glass door, watching as Tony stumbled around his sanctuary, clearly drunk. Tony suddenly stopped and stood up straight, determination in his eyes as he looked down at the reactor. He tightened his fingers around the lip of the metal and gave it a sharp tug.
Loki could not control the burst of magic, shattering the glass walls and doors to the lab, as he saw Tony collapse. He ran straight over to the man and put the device back into the man's chest, hoping that would do the trick. "You can't leave me Tony, please, don't leave me."
"You called me Tony," were the only words that Stark managed to whisper before passing out. Loki nearly sobbed in relief when he heard that voice.
"BANNER!" 5 minutes later the doctor ran into the room having been alerted by JARVIS and helped Loki to move Tony where he needed him to be. It was all Banner could do to contain the Hulk when he saw Loki standing over Tony's body but hearing the God pleading for help swung it in his favour. Loki explained what had been going on between the two of them as well as what he had watched Tony do before confessing to the doctor that he loved Tony.
The two men stopped talking when they noticed the man on the bed between them stirring, Bruce helped Tony to sit up slowly, giving him some water before laying the man back down and leaving the room so Tony and Loki could have a much needed discussion.
"Why am I here?"
"Don't you remember? You tried to kill yourself Stark."
"I know. Why didn't it work?" Loki felt his heart break at these words, he knew that Tony didn't return his feelings but he thought that they had something, even if it wasn't love.
"I saved you," Loki whispered, scared of how the man of iron would react.
"Why? I didn't want to be saved. I didn't ask to be saved. Why would you do that? You made it quite clear earlier that you don't want anything to do with me. You said that I was just a freak. Why would you save me?" Stark's voice was slowly rising in volume as he got more and more angry at the pale God for his actions.
Loki, however, could not raise his voice past a whisper when he replied, "I did it because I love you. I couldn't live without you." Tears began slowly flowing down his cheeks when he admitted this to the man on the bed and he sank to his knees, hiding his face in his arms, shielding himself from the man, from the outburst he thought was coming.
Loki did not realise that Stark had slipped out of the bed and knelt down beside him until he felt arms wrap around his shoulders. Loki tensed waiting for the man to make his next move, worried for the shouting or the hitting that he assumed was to come.
Tony however did neither of these thing, instead he placed a kiss to Loki's shoulder before laying his head there. "I love you too Lo, I thought that you didn't want me anymore, I couldn't live with that thought."
"I thought that you didn't love me like I love you, I couldn't keep lying to myself so I thought that I should end it, but I couldn't stay away. I came down to the lab to try and apologise but you locked me out. I had to stand there and watch you, I couldn't get to you. Don't do that to me again please Anthony. I'm so sorry. I love you, just please Anthony, I can't lose you again. I think I would follow you wherever if you had left this world." Loki was unable to stop the tears that flowed as a near constant stream down his cheeks.
Tony lifted Loki's face to look at him, wiped away the tears with his thumbs, placed butterfly kisses on both eyelids before kissing the man in front of him.
The two of them fought still after that event but never like they did that day, and they always ensured that they were back in one another's arms at the end of the day. They knew that neither of them would live through the events if they ever repeated and neither of them wanted that to happen. The rest of the team were apprehensive of their relationship at first but once they saw that Tony had cut back on the alcohol and Thor told them all that he no longer saw cuts appearing on his brothers arms they began to accept that they were helping one another.