Some Reddit communities dedicated to Spider - Man or fanfiction in general might also be a great source. Members often share and discuss their favorite fanfictions, and they might be able to point you in the direction of some great Peter Parker and Norman Osborn stories.
There could be a fanfiction where Peter Parker and Norman Osborn have to team up to face a greater threat than either of them has ever faced. This forces them to put aside their differences. They might start to understand each other better during this adventure, and it could change their relationship forever.
Mentorship is also a theme sometimes. Norman, with his experience and knowledge, could potentially be a mentor to Peter in some fanfictions, despite their differences. And there's the theme of secrecy. How they keep their relationship (whatever form it takes) a secret from the rest of the world and the consequences of that secrecy.
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.
The fanfiction often plays with the idea of power dynamics. Peter has his spider - powers, while Norman has his wealth and intellect along with his Goblin - related powers. Writers can create interesting storylines where these powers clash or are used in unexpected ways in their relationship.
You can try fanfiction websites like Archive of Our Own (AO3). There are a large number of fanfics on that platform, and you can simply search for 'Peter Parker kissing Harry Osborn' in the search bar. It's likely to return several relevant stories.
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.
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.
Archive of Our Own (AO3) is another great place. It's known for its wide range of fan - created works. Just use the search function and type in 'Norman Peter slash' and it should show you relevant fanfictions. It also has a great tagging system to help you narrow down your search.
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.
Some fandom - specific forums or communities might also be a great source. There are often members who share their own fanfictions or recommend good ones they've read. For example, there could be Marvel - related forums where fans discuss and share these types of crossover fanfictions.