A/N: Ukelx and I got talking about AoSxAvengers cross pairings and ended up decreating that Starkitz (yes it works shutup) was the awesomest ever and the cutest fluffiest thing full of science and coffee and cuddles. So here have some.
I have no idea what I'm doing. But as I'm guilty of instilling this pairing into my friend's mind, I will try to at least start to sate her thirst for romance.

WARNING: Slash fanfiction. Unusual (but not weird -i hope-) Pairing. Fluffy Flufferton.

Pairing: Tony StarkxLeo Fitz

Leo Fitz was never what you would call a playboy. Apart from the memorable moment when Lucy Goldstein and Amanda Barkoff both stole kisses from him behind a tree in kindergarten; being sought after with any kind of persistence was totally unknown to him.
Being asked to help Tony Stark with a few of his researches (deep space suits with portable satellite capacity to make communication easier, GENIUS -why didn't anyone at SHIELD ever think of that?-) had become a habit rather quickly after the Avengers were informed of Coulson's non-death, and then being frequently interrupted in his own researches (in his down time, even Stark wouldn't bother him during a mission… not after the reprisal he'd gotten from Coulson and Ward the last time he tried) by said Tony Stark, just to compare notes or talk shop.
Well he'll have to be excused for not immediately jumping on the "want to sex you up" wagon. He'd taken to Tony's ability to always be free when Fitz called him to discuss something and his increasing presence in his life like he'd taken to Simmons' or Skye's or even Ward's.
They were his friends and, if said friends' kept eye-rolling him anytime he mentioned his work or his talk with the billionaire these days, well they could have given him a bloody clue instead of just smiling like they knew the end of a joke he didn't get.
After six months of back and forth between the super-hero and him, Fitz had tentatively called what they had, a friendship and never dared to look at it closer again. But he probably should have.
Because he was now faced with the smirking man after having been given the most thoroughly arousing kiss he'd ever had in his life (take that Heidi Sandburg! He'd been kissed by a superhero! What do you say now, miss I-won't-kiss-you-because-you're-a-nerd?!).

"So. Clint and May said I needed to be more straightforward and that you might not have caught a clue of what I've been trying to do for the last… hell… for the last 5 months." Tony chuckled, hiding his embarrassment behind a wry grin and a saucy wink. "How was that for straightforward?"
"I… r-really? Me?... I mean… you're teammates with Captain Rogers and Specialist Barton and Specialist Romanov and…" Leo started babbling, red creeping on his face.
"Woah, slow down, Leo. Sure I'm in their team, they're awesome people if a bit scary sometimes (okay a lot of times for Natasha) but I don't want to screw their brains out…" The billionaire giggled a bit before wincing. "I mean, I don't want to screw your brains out. I mean yeah I do, but not only! I mean… your brain turns me on, man. I never thought I'd see the day when someone as smart as me wouldn't make me want to brain them with a club and you're just amazing with a schematic model and some scraps and..."

The SHIELD scientist who'd been steadily growing redder and redder as the older engineer continued talking, just raised his hand, stopping the flow of slightly embarrassing compliments.

"Let's… let's just take a moment okay. I just need a moment." The curly haired scientist breathed, trying to stop his heart from playing bongos around his chest.
"Uh sure." Tony nodded, looking around awkwardly.
"I mean… you're an amazing engineer Tony, and working with you is a frankly astounding opportunity to broaden my understanding of a lot of fields. But I never… I mean… I've never…" Fitz stumbled with his words, how could he explain to this accomplished fellow scientist who was also famous for his numerous conquests, that the only frolicking he's ever done was a regrettable alcohol-fuelled post-graduation sexual haze with Simmons which they had both vowed never to bring up again.
"Hey, if I really just wanted to have sex with you, I'd have done that when you first came down to my lab with me, 5 months ago." Stark interrupted his awkward revelation quickly, leaning slightly toward him with a strange frown. "I've tried to get you to accept at least a date with me, since maybe a month after that. But you never seemed to catch on. Apparently you're the only one who didn't and everyone else is being a dick at me about it."
"What? They shouldn't butt into something that's completely not their bloody business!" Leo frowned, feeling a surge of protectiveness toward the older man who he'd seen catch a lot of heat from SHIELD even when it wasn't his fault or his intention.
"Oh they know now, but I guess they just seem to think you like me back and you never said anything so I thought. Why the hell not, you know?" Iron Man shrugged a little, digging his hands into his pockets.

Fitz's mind was whirring madly, as he tried to come to term with this, it was the most ridiculously adorable conversation he'd ever been part of, even he could admit to that. And it brought to mind so many little attentions Tony had had over the months and why he'd seemed so relieved every time they came back from missions without a scratch or even his worry that one time he sprained his ankle while falling into a trapdoor in a disinfected factory. But his own head seemed to work on automatic as he thought back nearly against his own judgement, to all the occasions he'd just sat there in the lab, watching Tony's limbs moving elegantly as he handled holo-files and talked to JARVIS while dancing around the lab to grab some tool or other, bantering with his bots with that small paternal smile on his face. He remembered with perfect clarity most of the billionaires varying ranges of expressions while in the safety of his lab, where he didn't need to hold that plastic smirk that seemed glued to his face whenever he was out. From his concentration frown to the wide smile on his face whenever Butterfinger or You engaged in a game of tug-o-war with one of his old rags while trying to bring it to him or even that slight twitch at the left corner of his mouth like he's trying to repress a smile while berating Dum-E for whatever mischief he'd caused that time.

"Leo? You still with me there?" Tony's soft query brought the younger engineer back out of his own mind and face to face with the older man's warm brown eyes, veiled with concern.
"Your eyes wrinkle slightly on the corners when you smile and when you're worried." The curly hair Scot blurted before he could really think about came out of his mouth. "Your hand twitch to rub your arc reactor whenever you hear about Afghanistan and when you're really really tired, your public school accent comes out(**), really proper and I think it's kind of cute."

Fitz's hand came up to his mouth and he hung his head to hide his burning cheeks. He did not catch Tony blinking rapidly and then grinning impishly at his bowed head. Leo's eyes widened slightly when the billionaire's calloused hand gently nudged his head back up and stayed under his chin, his thumb caressing his cheek lightly.

"I'm going to kiss you now…" Iron Man warned him, in a slightly breathless voice, as he leaned in toward him.
"Okay…" The younger scientist replied, his eyes fluttering close as the other man leaned closer.

Their lips met again, a bit awkwardly on his part, and caressed each other delicately. Fitz then opened his mouth and had to repress a moan when his friend's tongue sneaked into it and started massaging the inside of his mouth with dexterity. Far too soon, Tony leaned back, his eyes riveted on Leo's face and more particularly his lips, as he tried to regain an even breathing.

"So… is this a date?" The billionaire asked, snaking his arms around the other man.

Not trusting his voice not to fail him, Leo nodded slightly, blushing again. He felt himself tense against the super-hero and tried to relax but couldn't help the ingrained reaction, although Tony didn't seem to notice or if he did, he decided thankfully to ignore it.

"Then we should get something to eat. There's a great pizza place, two blocks away. We could go there." Stark smiled brilliantly, nuzzling the side of Fitz's face as he cuddled the other man closer, letting the other man relax slowly in his embrace.

The young scientist nodded against him and finally able to relax a little more, let his head fall onto the other man's broad shoulder.

"Or we could order pizza and go to your lab. I had some modifications for an ice-gun I wanted to show you…" Leo mumbled against his shoulder.
"Man after my own heart." Tony purred in his ear before dragging him into another unhurried kiss. "I can't promise not to give in and kiss and cuddle you more while we're down there, though."
"Good… you have a blanket permission as long as it won't result in fire, destruction of invaluable properties or embarrassing pictures being leaked on the internet." The Scot retorted, letting a mischievous smile bloom on his face.
"Such a hard bargain Mr Fitz. I should steal you from SHIELD and make you my executive director after Pep'."
"As if you would stand before Coulson and May and tell them that. If you do, I want to be there to make sure they let me kiss you goodbye."
"Cruel, cruel man."
"You wish."

~Fin

I really suck at endings. I might add more to the Starkitz fandom of two that my friend and I just created XD But that will have to wait. Meanwhile, can anyone tell me if anyone's ever written/drawn/painted/recorded/done anything with that pairing? Cuz I couldn't find anything D:

(**) The public school thing. Fitz is Scottish, I take it for granted that he did most of his pre-PhD scholarity in England. So public school = private school. Sure the public school accent in England is different from in the US but you still recognize someone who's been to private school :P