The story could develop with Tony trying to reason with Steve. Tony might use his intelligence to talk Steve out of whatever his plan is. He could point out the flaws in Steve's reasoning or show him evidence that he's been misled.
Tony would likely be defiant. He's not the type to cower in the face of danger. He might immediately start looking for weaknesses in Thanos' setup and try to escape on his own terms.
Perhaps in a post - Endgame world, Tony didn't die but lost his memory. Steve takes it upon himself to help Tony regain his memories. Along the way, they re - explore their relationship, the Avengers, and all the events that led to that point. Steve shows Tony videos and tells stories, and slowly Tony starts to remember, leading to a renewal of their friendship and a new start for the Avengers.
I would recommend 'Steve and Tony: The Unlikely Pair'. In this fanfiction, their relationship starts off rocky due to their different ideologies but then blossoms into a strong partnership. 'Forging a New Path' is also worth reading. It shows how they navigate through political intrigue together while also strengthening their bond. 'The Promise of Tomorrow' is a heartwarming story that focuses on their hopes and dreams for the future and how they support each other in achieving them.
Not at all. Steve and Tony have a complex relationship in their own story. By listening to Tony fanfiction, he could be trying to gain a new perspective on Tony. It's like looking at a familiar painting from different angles. Fanfiction offers different takes on a character, and Steve might be curious about those interpretations.
In the fanfiction, Steve leaving Tony for Bucky could also make Tony more guarded in future relationships. He might be less likely to trust people easily, especially those who were close to Steve. And Steve, on the other hand, might be focused on building his relationship with Bucky, leaving little room for any kind of reconciliation with Tony.
Well, it could severely strain their relationship. Tony might feel betrayed and hurt. He could start to question Steve's loyalty. Since Steve is ignoring him for Bucky, Tony might become resentful towards both Steve and Bucky. It could lead to a rift that's hard to mend in the story.
On the other hand, Steve might be more understanding than expected. He knows about Bucky's past traumas and could suspect that something else is at play. So, instead of immediately resisting, he might play along for a while, waiting for the right moment to figure out what's really going on and how to help Bucky.
You can start by looking on Archive of Our Own (AO3). It has a large collection of fanfictions, including ones about Steve and Tony. Just search for the relevant tags and you'll likely find many great stories.