Tony might cut off his relationship with Steve completely. He's a proud man and wouldn't tolerate such betrayal easily.
The consequences can be quite severe. First of all, his friendship with Tony would be in shambles. Tony, being a genius and a man of strong emotions, would probably use his resources to distance himself from Steve. The Avengers as a whole would be affected. There could be a lot of tension and mistrust within the group. Steve's reputation among the fans in the fanfiction world would also take a hit. He might be seen as a villain or at least a flawed character. And depending on the nature of the fanfic, Steve could lose his leadership position within the team or face other forms of punishment or isolation.
In many fanfics, the other Avengers might take sides. Some would side with Tony, feeling that Steve's actions were unacceptable. This could lead to a split in the team. Steve himself would likely be filled with guilt and regret, as his actions go against his moral code. He would have to face the wrath of not only Tony but also those who support Tony, and it could be a long journey for him to redeem himself, if that's even possible in the context of the story.
I think this kind of fanfic can be quite controversial. In the Avengers universe, Steve and Tony have a complex relationship, and adding such a plot of 'cheating' with Bucky can change the whole dynamic. Some fans might like it for the drama it creates, but others might feel it goes against the original spirit of the characters' relationships.
The fanfic alters the perception of the characters in multiple ways. Steve's reputation as a trustworthy and noble character is at stake. His actions of 'cheating' are not in line with what fans usually expect from him. Tony, who already has a complex personality, now has another layer of being wronged added to his character. Bucky, who has his own set of issues in the official stories, is now part of this love triangle that further complicates his image. It shows how fanfics can reshape the understanding of beloved characters in unexpected ways.
There's also 'Unfaithful Hearts' which focuses on the reactions of their friends and the wider community within the fanfiction world. It's not just about Steve and Tony, but how their situation impacts everyone around them.
One possible reaction could be Tony's heartbreak. He might feel betrayed and angry, leading to a rift in his relationship with Steve. He could also become distrustful of others in the future.
One consequence could be that the Avengers split up. If Tony breaks trust, some members might not want to work with him anymore. For instance, Captain America, who values honesty and loyalty highly, may decide to lead a faction away from Tony.
On the other hand, it could also lead to new opportunities for character development among the remaining Avengers. They may be forced to step up and fill the gaps left by Tony. For example, someone else may have to take on the role of the tech - savvy member, which could bring out new skills and relationships within the team.
The Avengers may become less technologically advanced without Tony's genius. His inventions like Iron Man suits and other high - tech gadgets are often crucial in their battles.
Well, it's not super common but it does exist. There are different reasons for this kind of plot. Maybe the writer wants to explore the consequences of a breakdown in their relationship. They had their differences in the movies, like in 'Civil War', and some fanfic writers take it to an extreme by having Tony kill Steve to show how far things can go wrong when they can't resolve their issues.
One great Steve Tony Avengers Assemble fanfiction is 'The Road to Redemption'. It focuses on Steve and Tony's complex relationship as they lead the Avengers. The story has amazing character development and some really exciting action scenes.
One way could be through communication. Steve could come clean to Tony about his feelings for Bucky and apologize sincerely. Tony might be able to forgive Steve over time if he sees that Steve is truly remorseful.