A reason could be that Peter is reminded of Tony's last words to him. Those words were full of hope and trust in Peter. When Peter reflects on them, he is overcome with emotion and starts to cry as he feels the weight of Tony's expectations.
One possible scenario in such a fanfiction could be that Peter is crying because he misses Tony Stark after his death. Tony was like a mentor to Peter, and his absence leaves a huge void. Peter might be in the Avengers compound, looking at old photos or mementos of Tony, and the memories make him break down in tears.
One possible scenario in a fanfiction could be that Peter Parker is trying to hide his emotions from Tony Stark. Maybe he's been through a tough situation at school, like being bullied, but he doesn't want to seem weak in front of his mentor. Tony, on the other hand, has his own issues with showing vulnerability. He's always been the strong, confident Iron Man. But perhaps he starts to notice Peter's struggle and tries to open up about his own past traumas to encourage Peter to let it all out.
One possible reason could be a disagreement over superhero tactics. Peter, being young and idealistic, might yell at Tony if he thought Tony's methods were too extreme or not in line with his own sense of justice. For example, if Tony made a decision during a battle that put civilians at risk, Peter would likely be very vocal about it.
One popular fanfiction site is Archive of Our Own (AO3). You can go there and search for 'Peter Parker crying over Tony Stark' to find relevant stories. There are likely many works that explore the emotional bond between them and scenarios where Peter might be crying over Tony's death or other significant events in their relationship.
The theme of legacy is often present too. Peter might be crying while thinking about how to carry on Tony's legacy. He may feel the weight of living up to Tony's name and the expectations that come with it. Fanfictions may delve into Peter's internal struggle as he tries to figure out how to be the hero Tony believed he could be, all while dealing with his own emotions.
The relationship can start out a bit rocky in some fanfictions. Tony may be initially dismissive of Peter as just a kid. But as Peter shows his capabilities, Tony starts to take him more seriously. They then start to bond over their love for science and technology. Peter is eager to learn from Tony, and Tony enjoys teaching Peter new things. This mutual exchange helps their relationship grow from a mentor - mentee one to a true friendship.
One reason is to explore deeper emotional bonds. It makes their relationship more complex and intense.
The fanfiction could start with their individual backstories that led to this trouble crying. Tony's past with his parents and his journey as a superhero has made him suppress his emotions. Peter, growing up without a father figure for a long time, has learned to be tough. As they work together more often, small incidents start to crack their emotional walls. For example, a kind word from a civilian they saved makes Peter's eyes water a bit, but he quickly holds it back. Tony notices and it makes him reflect on his own emotional state.
One aspect of such fanfictions could be the way it challenges the traditional gender roles in superhero stories. Since male pregnancy is not a common concept in the original superhero lore, it can lead to interesting plot twists. For example, it might change the way they approach their superhero duties while also dealing with the physical and emotional changes that come with pregnancy.
The pairing of Tony Stark and Peter Parker in fanfiction is significant as it combines two very popular characters. Tony represents the experienced, high - tech billionaire superhero, while Peter is the young, enthusiastic, and street - smart Spider - Man. Their combination allows for a lot of character development. For instance, Peter can learn from Tony's mistakes and successes, and Tony can be reminded of his own youth and idealism through Peter.