The Avengers might start to see Iron Man in a new light. The fanfiction could highlight aspects of his character that they hadn't really considered before. This could lead to a deeper understanding and respect among them for Iron Man and also for each other as they discuss these new perspectives.
If they watched 'Iron Man 1' in a fanfiction, their relationships could shift. Tony's early struggles shown in the movie could make the others more protective of him. Thor might offer his friendship more openly. Natasha could start to trust Tony more, as she sees how he overcame difficult situations in the movie. And Clint might stop making some of the sarcastic comments he usually makes towards Tony.
They might become closer as they share a laugh over the fanfiction. Tony could be more open about his feelings after seeing how fans view him in the Iron Man 3 story.
Well, some relationships might become stronger. For example, Thor and Rocket might bond more over their shared experiences in Endgame. They could start to rely on each other even more in future battles.
They might become closer. Sharing the experience of reading or watching fanfiction could create new inside jokes. For example, if there's a particularly funny scene in the fanfiction, they could reference it later and laugh about it together.
In fanfiction, the Avengers could have a range of reactions. Hulk might not care much about the drama but be more interested in the destruction. Black Widow would probably be analyzing every move, looking for any weaknesses in the villains' plans. Captain America could be feeling a bit out of place with all the modern technology. And Iron Man himself? The others might be in awe of his ability to keep going despite all the odds against him in the movie.
They might be amused. Tony Stark himself would probably be quite smug, seeing all the creative ideas fans have about him. Steve Rogers might be a bit confused at first by some of the more out - there concepts in the fanfiction. Natasha Romanoff would likely be quietly observant, picking up on the different characterizations of Iron Man in the stories.
They could become closer. Sharing a laugh over some of the wilder fanfiction plots would create a new bond. For example, if there was a really out - there story about Hawkeye and Black Widow having secret superpowers, they could joke about it together.
Some relationships might become stronger. If they read fanfiction that shows deep friendships between them, they could be more aware of their bond. For example, if there are stories about Iron Man and Captain America's friendship overcoming differences, they might be more likely to work together better.
They would probably have a lot of banter. Tony would be making snarky comments about his own actions in the movie, and Steve would roll his eyes at some of his more egotistical moments. Thor might be sharing his thoughts on the magic - like technology, which would be really interesting. Natasha and Clint would be sharing knowing looks during the more intense scenes.
Conversely, relationships could also be strained. If the fanfiction portrays a character in a way that another character doesn't like, such as making one character overly jealous or possessive of another in a way that goes against their normal dynamic, it could cause tension between them. For instance, if a fanfiction makes a brother - sister relationship seem romantic in a wrong way, it would create problems.