"Leo Fitz x Tony Stark"

"I can't believe you've got a goddamned Star Trek reference in your soulmark," Tony said, running his thumb along the words again. Leo understood the fascination; he wished he could see Tony's soulmark, but it was habit for his soulmate to cover the words in fear of someone attempting to exploit them. Not that they had to worry about anyone trying to fake being his soulmate now that he and Leo had found each other; it was news, however, that they were keeping from the press for as long as possible.

"At least it set me on my career path," Leo said sleepily, running his fingers through Tony's inky black hair. "Either an engineer or playing Scotty in a remake. Yours has me calling you sir. And asking you for help. Christ, at least your words on me are original."

"Yeah, but 'better be interesting'? I sound like such an asshole."

"You're my… y'know, I won't finish that, because I have a terrible habit of accidental innuendo. You'll see that."

"I'm already seeing it," Tony said. He inhaled deeply, and rested his hand over Leo's soulmark. "Well, I deliberately create innuendo out of everything, so we're perfectly suited. Aside from being two hot engineering geniuses." Leo dipped his head, looking away. "You are. Don't do that thing… you're doing that…" Tony hauled himself up the couch and turned Leo's head around to face him. "Accept that I lo… that you're perfect to me, just like you once said I was perfect to you. Remember that, the day we met?"

"It was only a week ago," Leo said.

"And I was the desperate old man who begged you to say that we were soulmates," he said, and he swallowed. "Too long without you, kinda drove me nuts. When you were born I was still off the rails sometimes, and I was probably in one of my engineering frenzies. Not even Stane knew my words. In hindsight, a fucking good thing."

Leo wrapped himself around his soulmate.

"If he was still alive I'd kill him for you," he said quietly. "And you're not old. You could never be old. You're too full of life." Tony hummed, and this time he was the one threading his fingers through Leo's curls.

"Maybe I should say it," he said.

"Say what?" Leo glanced up at him. "What you almost said before?"

"Yes."

"…Only if you don't think it's too soon."

"We're soulmates, Leo. I'd be surprised if you didn't…"

He cleared his throat. "I do. If that's what was keeping you from saying it."

"You…?"

"I love you, Tony Stark."

In the next second he was flat on his back with a handsome billionaire attached to his mouth. Leo tried to keep up, but Tony was skilled at this, and he seemed to have more hands than most mortals. His shirt was already unbuttoned, so that Tony could continue to play with his soulmark; now the shirt was slipping off, and Leo whimpered as he was pressed down into the upholstery, Tony's singlet rubbing against his sensitive skin. Tony wrenched himself off and fell onto the cushions beside Leo.

"Damn it. I wasn't gonna rush you."

"Did that really look like you were rushing me?"

He shrugged helplessly. "I've never been in an actual relationship before. The closest would've been Pepper, until she found out that Hill was her soulmate, and then I had to let her go, no question. Of course, Hill's now in the doghouse for keeping Coulson's resurrection secret from us, especially Pepper." Leo raised an eyebrow, not that Tony noticed. "It's only ever been straight to bed with me. I'm not screwing this up, not with my soulmate. There's too much at stake."

"It's been a whole week, Tony—"

"And I'm doing this right. I know you can't let your mother know that you're alive, and we don't know where all your people are. But as soon as we get them all together, I… I want to make it official between us first."

Leo stared at him. "Official, as in…?"

Tony rolled off the couch, and stalked over to one of the benches in the lab. Leo sat up, wondering at the change in mood. He was glad Tony had had a large couch installed in the workshop, because it meant cuddling between projects, and they actually managed to get some sleep as well. Only with clothes on so far, but now that Leo knew for sure… well, not for surely-sure, but close enough… well, he was going to keep working on it.

Half a minute later, while he was still thinking deep thoughts, he saw shoes, and looked up just as Tony knelt before him. On one knee, and holding a small box.

"Leo Fitz, I love you, so will you m—"

He'd let Tony finish in a minute. Meanwhile, Leo pounced, nearly knocking him over, and he had to kiss his soulmate until they both nearly ran out of oxygen. Slowly, nightmares of being unable to breathe had receded in favour of being kissed breathless by Tony Stark. Once the worst of the impulses passed, he retreated to where he'd been sitting, a bit jelly-legged, and gestured for Tony to continue.

"Will you marry me in a real bonding ceremony? Please say yes. We can go as traditional as you want. I want to prove how serious I am, and… and make sure you won't run off when I get unbearable." Tony's eyes turned sad as he said this, and Leo's heart ached for his soulmate. "I'm not saying you would, but I need this to…"

"I understand," Fitz said, and he cupped Tony's cheek. "Yeah, I'll marry you. Like you even had to ask. If ever I build a time machine, I'm going back in time to cuff your father around the head for making you this insecure."

"That would explain that night he came home complaining about how some curly-haired Scotsman attacked him for no reason," Tony said, his eyes widening to a ridiculous extent. But then he grinned, and Leo couldn't help jumping him again. This time, however, he was careful not to knock his fiancé over.

Fiancé! He could hardly believe it. He couldn't wait to tell Simmons.

When JARVIS sent him a discreet alert, Tony shut down his current screen, waited for Leo to save his, and then grabbed him by the hand.

"Come with me," he said.

"Where are we going?" Leo asked, allowing himself to be dragged along to the elevator.

"Guess," Tony said. He tugged his fiancé near when the doors closed.

"Is it lunch-time?"

"Nope."

"Have you been assembled? Surely I didn't miss that announcement…"

"Guess again."

Leo seemed to give it some thought. Then his pupils dilated as he looked Tony head to toe, and he licked his lips. Tony seriously began to reconsider his vow of celibacy before the bonding ceremony.

"Are you finally taking me to bed?" Leo said, and he met Tony's eyes.

Fortunately, they arrived on the roof at that moment, and Tony breathed a sigh of relief when the doors opened and the light poured in. It was afternoon, and the eastward-facing doors had opened to protect their workshop eyes from the brightness, but it was still sunny enough to make the figures blurry for a few seconds. Then the people Barton had flown in started moving their way. Leo gasped, and looked at Tony, who merely smiled and shrugged.

"Found your wedding party," he said.

"Oh my… thank you!" Leo threw his arms around Tony's neck and kissed him repeatedly between thanks.

"Don't… kiss me," Tony said, gripping his soulmate's hips. "Go say hi to your friends!"

With a final kiss, Leo ran off, and into his team's arms. It was weird seeing Coulson, who they'd known long before these strangers, being all friendly with them. Barton rested an elbow on Tony's shoulder.

"He was never like that with us," he said. "It's like he's forgotten how to be professional around junior agents. He's become Papa Phil."

"I know what you mean," Tony replied. "I don't know how I feel about it. He's been alive all this… most of this time, and he never told us. Now he's the director of a new SHIELD, and we're barely a blip on his radar. He's only here because of Leo."

"Who's only here because of Coulson."

There wasn't much Tony could say to that, especially as the others approached. Barton clapped Tony on the back and sauntered over to the elevator, which was still waiting for them. Tony insisted on having introductions inside, where no one would have to squint to see, and when they were all crammed in he pulled Leo into his arms and wouldn't let go, making sure they understood completely. Coulson gave a small nod, acknowledging this, and Tony turned his attention to the introductions. He shook hands with Leo's friends, keeping one arm around his soulmate at all times, the marks brushing close together and separated only by clothing.

"When's the wedding?" Hunter said.

"Not a wedding," Leo replied. "Bonding ceremony. As soon as possible, now that you're all here, because Tony's withholding se—"

Tony covered Leo's mouth, and felt his cheeks heating up like they hadn't since he was a teenager. Judging by everyone's looks, they knew exactly what Leo was going to say.

"Not in mixed company," Tony said, lowering his hand. "There are ladies present."

"Until after the ceremony," Leo said, thankfully missing the bit about celibacy, even though it was pointless trying to hide it.

"A bonding ceremony," Coulson said, studying Tony. "That's very permanent of you."

"Bonding is permanent," he said. "Leo's my soulmate, and I want to make it clear to everyone that nothing's going to part us. I'm not giving up…" He hated pouring out his feelings in front of strangers. "I'm not giving him up. A bonding ceremony will prove it."

After that declaration, Barton led them into idle chatter until they reached the common area, where Coulson was going to get disappointed faces from more people.

It was true. A bonding ceremony was far more significant than a wedding. Bonding was generally private, especially considering the positions some soulmark placements suggested. Tony and Leo could bond in front of others, but it would involve Leo's chest being bared, and Tony wasn't fussed on the idea of other people seeing that much of his soulmate. He'd do whatever Leo wanted, of course; Tony bought whatever he thought his fiancé would like, whatever he'd need, beg for suggestions from Leo (who lived on way too little, which Tony found unacceptable).

In the days of modesty, as long as soulmarks were fairly close together it counted. It was about the intensity of the soulmates' feelings for each other, which could very well form a pre-bond without contact. Tony felt strongly enough for Leo that he knew a bonding ceremony could work for them. It could. They hadn't gone over the details yet, but Tony was prepared for all the traditional vows, if that's what Leo wanted.

Damn, he was lucky.

Leo tried to push Skye's hands away from his hair, and Jemma's away from his collar.

"Not even a tie?" she said. "Come on, Fitz…"

"Nope," he said. "I asked you lot in here to calm my… my…"

"Nerves?" Skye suggested.

"That. Not to fuss over… this." He indicated his simple outfit. They weren't having the ceremony outside, so he didn't have to rug up. He was wearing a loose button-up formal shirt, short enough not to be tucked in to his black trousers, and he'd chosen a belt which had two linking metal arms, rather than a buckle (to save time later). He doubted he would have to open his shirt, but he wanted to be prepared. It was only fair, since Tony's soulmark would be on display with his short sleeves.

"You look very nice," Jemma said.

"I don't need to look nice," he grumbled.

"No, but you'll be grateful for it when you look back over the pictures one day."

"…Can't argue with that."

"Come on," May said. "Your groom's waiting. You don't want him to think you're running away, do you?"

Leo squared his shoulders. "Absolutely not. Let's get going."

So it was that three minutes later he was at Tony's side and holding his hands. Director Coulson, as the only direct link between the two of them, had agreed to lead the ceremony, welcoming the guests, making sure everything went in order, and prompting them with the vows. A warm sensation grew in Leo's chest as he vowed his soul to Tony, and it was repeated back to him. Then Tony tugged Leo forwards, turned him, and slid his arm around so that the only barrier between their soulmarks was Leo's shirt. It took him back to a few days ago, when they were all in the lift and Tony publicly declared his claim without even realising it. He leaned back into his soulmate's hold, and let the warmth comfort him. The scratch of facial hair in the crook of his neck was the only warning he had before Tony breathed into his ear.

"I love you, Leo," he whispered.

"I love you, Tony," he said, turning his head enough to catch a glimpse of brown eyes.

Coulson was saying something, but he couldn't pay much attention while intense thoughts buzzed through his head, and feelings churned in his gut. He reached out, rested a hand over Tony's arm, and swallowed the lump in his throat as tears pricked his eyes.

"Damn it," Tony hissed. He jerked his arm away, then shoved it up beneath Leo's shirt, bringing their soulmarks into contact. It was electric. The feelings intensified, and he realised that he'd been feeling what Tony could feel. Their pre-bond had already formed, and this was the real bond taking place. He tilted his head around and felt Tony's lips meet his. This was more intimate than anything he'd ever felt before, and every scrap of insecurity was being overcome by such intense affection from his soulmate that he wondered whether he'd ever feel this good again, whether Tony could feel how much Leo loved him in return.

The first flush of the bond faded, and Tony moved his arm down. Leo finally met his eyes again, panting, and the moment was only broken when someone spoke up.

"Does that usually happen?" Colonel Rhodes said. Coulson cleared his throat.

"I don't think so," he said.

"Enjoy the party," Tony said. There was a wild kind of look in his eyes which gave Leo the shivers. "We're… going. Away."

Then he hauled Leo up into a fireman's hold and headed for the lift.

"Hey! Put me down!"

"Don't say you don't want this, because I know you do," Tony said.

"Yes, but…" He poked Tony's behind. "Not like this. This is not romantic. You carry me properly, Anthony Stark." With a sigh, Tony put him back down, then swept him up into his arms in a bridal hold.

"Is that better?"

"Much." Leo looped his arms around his soulmate's neck. "Continue."

With a twinkle in his eyes, Tony took Leo upstairs to what would now be their quarters, and threw him onto the bed, before diving on top. Leo laughed loudly as Tony tickled him, rubbing his nose along the vein in Leo's neck. It was nearly enough to distract him from his clothes being stripped off. He kicked off his shoes, hoping that there was nothing valuable in the room that could end up broken. Then he pulled and pushed at Tony's clothes until he was bare as well.

"That's amazing," he said breathlessly, tracing around the arc reactor. Tony pulled back. "I'm sorry. Did that hurt?"

"Not… not physically. It's the memories, the thought I could've died before meeting you, that my weapons could've killed you." He lowered his head. "Then I remember that my tech was in the Helicarriers, and that I didn't find out that HYDRA was in SHIELD, and I couldn't protect you when… when Ward…"

Leo cupped his face, Tony's despair welling inside him.

"Don't," he whispered. "I'm here now. We're here. We're bonded, Tony. No one can take that away from us. We've had the ceremony, and this evening or tomorrow we'll check and see whether Thor and Steve have left us any cake." Tony chuckled, loosening up. "An' now, if you don't mind, I'd like you to m-make love to me."

"With pleasure," Tony said. He dipped down to kiss Leo on the nose, then the lips, and then ran his fingertips over Leo's chest, making him giggle. "Now, now."

"Stop tickling me!"

Tony retracted his hands, and then fumbled about on his bedside table until he hooked a small bottle of lube.

"Should we shower first or—"

"I've waited two weeks for this."

He blinked. "Leo, we only met two weeks ago."

"Exactly. Although considering how long I've had a crush on you… well, you could say I've been waiting a hell of a lot longer. So kindly stop wasting time and get inside me."

Tony was extremely patient, to an annoying extent, especially when Leo felt echoes of his amusement. He couldn't deny squirming with frustration until Tony growled. He went still, and then he felt Tony's worry that if he wasn't careful, he might hurt Leo. It humbled him, and he forced himself to relax, and not push. Everything was so much sweeter when the burn was negligible, and he exhaled shakily as Tony bottomed out. The withdrawal was slow, and stole Leo's breath with the gradual slide back in. He wound his fingers into Tony's hair and pulled him in for a kiss.

After that, time blurred. There was no hurry, just a growing bundle of sensation, which didn't so much explode as consume. Leo shuddered, winding his right leg around Tony's back, and rocked upwards to keep the rush of bliss going for as long as possible. He wouldn't be surprised if it lasted only seconds, nor would he be surprised if it lasted a lifetime. He whimpered when Tony seemed to pull away, but instead rolled Leo onto his side. He carefully withdrew, then settled behind, and pulled Leo against him until their soulmarks met again.

"Damn, that was good," Leo mumbled, exhausted, and Tony chuckled.

"Which part of it?" he asked.

"You," Leo said, and he fell asleep, safe and warm and loved.

Because I'm a romantic fool, as you should all know by now.

I loved the idea of Fitz and Tony bonding in an actual ceremony because they just couldn't wait until they were alone, and it was (fairly) modest. Then I had to do the slow love-making, because it was requested by a reader on AO3, and it made so much sense for this rare pairing.

Please review!