There comes a point in their partnership that cracked the growing bubble of trust and love between them.
Steve feels like Tony is being elusive and sudden paranoia has him designating Natasha to follow him around for a couple of days. Natasha tells him it’s a bad idea but Steve is too caught up in his insecurities to listen.
Tony notices that Natasha is following him (he’s Steve’s second in command for a reason) and confronts her. She lets him know it’s for protection and just to humor Steve (which is not technically a lie) and Tony is mollified. But she watches him go into a house with a strange woman and then come back out about 20 minutes later, shaking her hand and parting ways.
When she tells Steve cautiously, letting him know that he should talk to Tony before any conclusions are drawn, Steve corners Tony and rants at him. “I trusted you! I gave everything to you! What are you doing, sleeping with a don’s daughter behind my back? Angling to get your own crew?” Tony’s face is purple with rage when Steve is done, his arms tensed and fists balled tightly.
Tony’s voice is deadly calm as he rips into Steve, telling him in no uncertain terms about the realtor he had gone to visit because Steve’s childhood home had come up for sale and he knew that Steve wanted a place to nest. Steve opens his mouth to say something but Tony cuts him off, tone icy and eyes hard and closed off. “I can’t believe you! How dare you say something like that when I have given my life for you and everything you’ve wanted. I follow your orders, even when I know you’re wrong. I gave you my heart and my trust and now I find out that you can’t be bothered to do the same for me.”
His voice was low and deadly as he said, “Fuck off, Rogers. I quit.” and stalked away.
He disappears. Steve knows that if Tony doesn’t want anyone to find him, no one will. He’s furious with himself and takes it out on his team until everyone is overly cautious, fearing one word would set him off and send them to their destruction.
Word gets out that Tony’s no longer a part of the team and everyone knows that Tony was a genius at weaponry and manipulation and charm. People aren’t scared of Steve’s crew anymore – half of it’s leadership left and Steve is out of control.
Natasha looks for Tony, desperate to get their crew back. She takes Sam and Rhodey, hoping that their logic will prevail. Rhodey tells them Tony’s most likely hiding spots but it still takes them a year to find Tony, a long year that finds Steve’s crew sparse and the damage to his business exponential. Tony has mellowed in his anger but is still bitter at Steve’s lack of trust and respect.
They plead with him to come and hear Steve’s apology (the one that he sobs out at night when he’s drunk and despairing). Tony agrees reluctantly.
The first time Steve sees Tony, it’s across a large room where they do their planning. Steve’s yelling at a strategist in a fit of rage when he looks up and meets Tony’s eyes. Tony looks both worried and knowing, as if he knew how Steve was breaking inside.
They meet in the middle of the room, Steve’s eyes asking for permission and Tony nodding softly. Steve pulled him into a tight, fierce embrace as everyone else left quietly, giving them space. Steve broke down, rasping out his apology into Tony’s hair while Tony pressed his tear-stricken face into Steve’s chest, nodding his forgiveness and whispering his own apology.
They’re on the floor, Tony stretched across Steve’s lap and Steve sitting against a wall, trading stories over the past year. Steve admitted that the situation was dire to Tony and he screwed up his face, thinking for a moment, before suggesting some ideas to help with the situation. Steve is caught up in a sudden rush of affection and lust that he kisses Tony fiercely, nipping at his lips and licking his way into Tony’s mouth, reveling in the taste of him. Tony clutches at Steve’s hair, pulling him close and whimpering into the kiss.
They pull back, panting with reddened lips, and Steve suddenly says, “Marry me.” Tony blinks slowly.
“Marry me.” Steve said desperately. “I never want to have to go without you again, I hated it, you’re my world, Tony. Marry me so that we belong to each other forever, even through our stupid mistakes. Please, Tony, I need you here with me.” His voice broke and Tony cupped Steve’s chin in his palm.
“Yes.” He says softly, lips curving into a small, soft smile.