One reason could be a difference in ideology. Steve might have very traditional views and Peter's more modern or reckless approach could clash with that, leading to Steve's outburst.
In the 'peter gets punched by steve fanfiction', it could be that there is a power struggle. Peter might be gaining power or influence too quickly in Steve's eyes, and Steve feels the need to put him in his place. Another possibility is that Steve is under some sort of mind control or influence of a villain, which makes him lash out at Peter without his normal self - control.
Well, in a 'peter gets punched by steve fanfiction', it could be that there is some sort of misunderstanding. Steve might think Peter has done something wrong, like endanger the safety of others or break a moral code in their world. Or perhaps it's part of a bigger plot where an outside force is manipulating Steve into attacking Peter.
He might think it's not in line with the real Steve. Fanfiction can be quite far - fetched sometimes.
Maybe Peter punches Steve because of a misunderstanding. For example, Steve might have been wrongly accused of something that Peter holds dear, like endangering his family or friends. In his anger, Peter decides to take matters into his own fists.
Perhaps Steve leaves because of a personal sacrifice. He might discover that his presence is putting Tony and Peter in danger, like there's a villain targeting those close to him. So, to keep them safe, he leaves without much explanation. It could also be that he has some unfinished business from his past that he has to attend to alone, which forces him to part ways with Tony and Peter.
One possible reason could be a misunderstanding. Maybe Steve Rogers made a decision during a mission that Peter Parker thought put civilians in danger. So in a fit of anger, Peter punches him. For example, if Steve chose to sacrifice a small area to save a larger one but Peter had friends in that small area.
Perhaps Steve in the fanfiction was involved in a cover - up of some sort that affected Peter. Say, Steve knew about a threat coming towards Peter but didn't tell him in time because he thought Peter couldn't handle it. When Peter found out, he felt betrayed and thus couldn't forgive Steve. Also, if Steve accidentally caused harm to one of Peter's friends or allies while on a mission, that could be a major factor in Peter's unforgiveness.
Steve could start by simply listening to Peter. Just let him rant about whatever is bothering him. Then Steve might offer some words of wisdom, like 'Peter, we've faced tougher things before and come out okay.' Another way could be a reassuring touch on the shoulder, a physical connection to show he's there for him.
The plot might involve some family drama as well. Steve's new - found fatherhood could cause issues with his existing relationships or responsibilities. Peter, on the other hand, might struggle to accept Steve as his father at first, especially if he has grown up without a father figure. But over time, they could build a strong bond through shared experiences and mutual understanding.
Another characteristic is the exploration of their different powers and skills within the story. Steve's super - strength, Tony's high - tech gadgets and Peter's spider - like abilities are often used in creative ways to overcome obstacles. This can lead to really exciting action sequences.
One possible plotline could be Steve Rogers seeing Peter Parker's potential and the similarities between himself and Peter. He decides to take Peter under his wing, much like he did with Bucky in a way. Steve could teach Peter about responsibility, not just the superhero kind but also in life. For example, he might show Peter how to balance school, family, and being Spider - Man.