Nobody actually ever told Steve that Tony doesn't like to be handed things until Tony himself had to.
He had been given a file before the whole issue with Loki but that mostly concerned Iron Man and the capabilities of the suit. Tony and his grand array of personality quirks were left out.
It happens when he manages to confuse himself while using his Stark Phone. He tries for a while to figure it out himself, but as he's really nervous to touch the thing in case he makes it worse that is clearly not happening.
Tony said, when he first received the phone, that he'd help him if he ever needed it, so, ok, he'll go and ask Tony.
'Tony?' he calls across the music when JARVIS lets him into the workshop.
'Mute,' he sees Tony's mouth move as he turns to face him rather than actually hearing the word and then the music cuts off. 'Cap, how can I help you?'
Steve smiles winningly,
Tony smirks at him,
'This must be a big problem, Cap, for you to be bringing the problem to the CEO.'
Steve blushes as he walks over and then holds out his phone to Tony,
'I can't find the start screen that I recognise,' he informs him as Tony eyes the phone.
'I don't like being handed things,' Tony informs him casually. His hands are pressed to his thighs as he peers closer at the phone.
'Oh,' Steve pulls his hand back containing the phone, unsure how to continue.
'Put it down,' Tony instructs then immediately picks it up from the workbench.
The solution is so simple that Steve is a little embarrassed. Tony doesn't seem to mind though and talks him through using the phone again and tells him to always come down if he needs a hand.
He also tells Steve he's going to send Fury the bill for Tony's time, but he's grinning so Steve figures even if he actually does send Fury a bill at least Steve was the one to put that smile on his face.
It's later when he thinks back over their interactions and realises that of course he has seen people hand things to Tony. He'll pay closer attention in the future.
Pepper can hand things to Tony.
This, honestly, doesn't surprise Steve. They've broken up but they still love each other and he's not sure Tony could ever bring himself to love someone he didn't trust.
He is certain that trust is the issue here; it can't be an OCD germ thing or putting the item down wouldn't solve anything, so he must be half expecting to be grabbed or something. Steve tries not the dwell on all the possibilities that could make Tony react this way.
But yes, Pepper can hand Tony things.
She turns up at the tower while they all happen to be lounging in the kitchen and takes the glass of juice out of Tony's hand and holds out some paperwork.
Steve unconsciously tenses to see what Tony will do.
'Well, good morning Ms Potts,' Tony just accepts the paper and pen and starts signing.
'Good afternoon, Mr Stark,' Pepper retorts with a fond smile.
'Is it already?' Tony asks without looking up.
'It is four in the afternoon, sir,' JARVIS confirms.
'Who knew?' he responds and trades the paperwork back for his glass.
Ok, so he trusts Pepper more than he trusts Steve.
Steve can live with that; they've known each other a really long time.
Rhodey can too, which is also fair as he's Tony's best friend (who isn't JARVIS).
It's him that dispels the possibility that Tony just doesn't like being handed things technological or possibly dangerous verses the paper Pepper gave him.
Rhodey hands Tony a giant gun. Barrel first.
'You know I'm out of the weapons business, right?' Tony abandons watching the TV with the others and carries the gun to the bar.
'Yeah, like I'm going to let anyone else mess with this,' Rhodey scoffs and the two of the fall into banter surrounding the uselessness of army tech experts.
Steve wonders how long he'll have to know Tony before he'll be able to hand him things.
OK, this time Steve is a little put out.
Tony accepts things from his bots.
Dummy, Butterfingers and You can all hand him things.
Just yesterday You handed Steve a handful of broken glass; Steve feels that Tony's trust in them may be undeserved.
Or maybe You doesn't like him; that's possible.
Anyway. While he's downstairs being still and quiet, and so invisible to Tony, he sees the bots hand things to Tony all the time; tools, drinks, food… the list goes on.
Tony is massively dependant on his bots though, Steve reasons with himself. Socially, if nothing else, they are his main constants.
It's then that Steve realises that he's determined to stay around Tony long enough to count as a constant.
Bruce can't hand things to Tony.
Steve really, really shouldn't feel better about that.
Whenever he needs to give something to Tony he does exactly as Steve had to with his phone. That he doesn't need prompting, like Steve did, just means that he's adapted to this quirk of Tony's. They do spend a lot of time together.
Steve tries not to feel jealous.
And then freaks out a little when he realises that he is.
Bruce is the first person Steve actually speaks to about Tony's issues.
'I don't know why,' Bruce looks up from his work and over his glasses at Steve. 'But if it makes him more comfortable then it's the least I can do as he trusts me more than nearly everyone else on this planet.'
It's hard to argue with that.
Especially when, after an unfortunate accident involving a half-rewired toaster, it turns out Hulk can hand things to Tony.
Long story short Bruce is electrocuted and Hulk emerges in the communal area. Steve, Clint and Natasha are all there at the time and back away slowly. Steve scans the room for the best way to get out and possibly get to his shield. He guesses the other two are thinking along the same lines.
It's then that Tony wanders in and beelines for the coffee machine; his path takes him right past the Hulk.
'Tony!' Steve hisses and just gets a dismissive wave in response.
Hulk makes a frustrated noise and crushes the toaster with one hand.
This gets Tony's attention.
'Oh,' Tony says, demonstrating every single on of his IQ points.
'Just back away,' Steve forces his voice to keep calm.
'You know,' Tony looks up into the Hulk's face, 'I was honestly expecting this to happen a lot more quickly.'
The Hulk just stares at him seemingly thrown by this reaction. Steve sympathises.
'What happened?' Tony turns to look at them and so displays his back to the Hulk.
'Electric shock,' Natasha is handling this surprisingly well considering what happened the last time this happened unexpectedly. 'From the toaster.'
'We needed a new one anyway,' Tony grins and turns back.
'Tony?' Steve is aware he sounds a little desperate.
'It's fine, Cap,' Tony pats Hulk's arm. 'He won't hurt me.'
'Famous last words…' Clint mutters as Hulk shifts his weight.
Steve is going to throw caution to the wind and just make a grab for Tony but before he can Hulk swings his arm towards Tony.
And just holds out the crushed toaster.
'Broke toaster,' Hulk informs him.
'Yeah you did,' Tony looks at it for a long moment.
Impasse, Steve thinks.
Tony takes the toaster.
Steve tries, and mostly fails, not to feel jealous.
Hulk huffs at him as Tony turns the toaster over in his hands,
'You've done a number on this, Big Guy. I'll salvage the metals from it though,' he puts it down on the side and returns his attention to the coffee machine.
There's a truly awkward silence as the coffee machine hisses and the present Avengers, minus Tony, all stare at each other. Tony downs the first mug of coffee, after splashing cold water in it, and cradles the second as he moves back across the room.
'Stark!' Natasha snaps then actually recoils a little when Hulk's head swings towards her and his nostrils flare.
'Come on, Big Guy,' Tony calls without turning around.
There's a pause.
Then Hulk follows him.
'Fuck me, Stark has some balls,' Clint sums up the proceedings as Hulk vanishes up Tony's private stairs.
Well, Steve tries to be optimistic whenever possible, this is good news for team dynamics.
Steve watches Tony turning elegantly on the dance floor with Pepper and wonders, not for the first time, how two such good friends couldn't make it work.
As the song ends Tony passes Pepper to another man and flashes his Tony-Stark smile as he leaves the dance floor. Steve joins him at the bar as the bartender has produced a martini with no prompting and placed it on the bar.
'You're a good dancer,' Steve smiles at him.
Tony offers him a more honest smile,
'It's helped me get laid more than once,' he replies flippantly.
Steve just smiles. Tony gestures off to the side and they move away from the bar. They stand together and watch the crowd.
They chat until another young lady comes to claim a dance from the great Tony Stark and steals his drink, which she gives to Steve, as she loops her arm through Tony's. Steve watches Tony show off for a few songs before he passes the lady on and returns to Steve's side.
'Oh,' Steve casts his gaze around for somewhere to put down Tony's drink.
'Wait…' Tony half reaches out his hand, a look of concentration on his face.
Steve keeps very still.
Tony's fingers just brush the glass before he jerks them back to his side with a choked gasp before grinning wildly,
'I'll get this,' he tells Steve, pointing his finger. 'I will.'
Pepper materialises at Tony's side with a bright smile on her face,
'I told you,' she tells Tony warmly. She takes the glass from Steve and hands it to her boss.
'Alright, this time you really get the credit,' Tony wraps an arm around her waist and takes a sip of the martini.
'You…?' Steve tries to query without being rude.
'You're dangerously close to no longer being able to keep things from me,' Tony grins at him.
Steve beams back at him.
This is more than Steve was hoping to get out of this evening.
And Tony looking that gorgeous with that smile on his face doesn't hurt either.