Peter would likely be defiant. He has a strong moral compass and wouldn't easily give in to Osborn's demands. He'd probably try to find a way to escape right away, using his spider - abilities like climbing walls and his super strength to break free from any restraints.
Well, one possibility is that Spider - Man's friends, like Ned and MJ, would quickly realize he's missing. They might start their own investigation, using Ned's tech - savvy skills to try and track Peter. Maybe they'd find some clues that lead them to one of Osborn's secret lairs. Another thing could be that Peter manages to break free on his own using his spider - powers and his wits. He could then turn the tables on Osborn and expose his evil plans to the public.
Peter would probably be scared at first. He's just a kid, after all, and being kidnapped by a powerful being like Thanos is terrifying. But he would also be defiant. He has a strong sense of responsibility, so he might try to find a way to escape on his own.
Peter would probably be really confused at first. He looks up to Tony, and suddenly being kidnapped by him would be a huge shock. He might try to talk to Tony, asking him why he's doing this.
One idea could be a story where Peter tries to protect Harry from the darker aspects of their world. Since Peter has his Spider - Man powers, he could be constantly on guard to keep Harry safe, perhaps from the enemies he made as Spider - Man. For example, a villain might target Harry to get to Peter.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you can easily search for Peter Parker and Harry Osborn stories using the search bar. Just type in their names and you'll get a list of relevant fanfictions.
There's also 'Friendship Forged in Crisis' which is an amazing Peter Parker and Harry Osborn fanfiction. It focuses on a major crisis in the city where they have to rely on each other completely. The story has a lot of action and also some really touching moments between the two characters that really bring out the essence of their friendship.
Since Peter is Spider - Man, he has to be careful not to use his powers and reveal his identity. So he might just try to defend himself in a non - superhuman way, like using his quick reflexes to dodge Flash's blows as much as possible while trying to calm Flash down verbally.
Peter will probably be very confused at first. He's used to being part of the team, and suddenly being hunted by them is a huge shock. He might try to talk to them to clear up any misunderstandings.
Stiles usually reacts with a mix of fear and defiance. He's afraid because he's in a dangerous situation, but his strong - willed nature makes him defiant. For example, in many fanfictions, he'll shout at Peter, trying to show that he won't be easily broken.
Peter usually blushes a lot. Since he's a shy and somewhat awkward teenager, his face turns bright red when the Avengers embarrass him. He might stutter while trying to defend himself or come up with an excuse.