Peter might initially be in a state of shock. He could isolate himself from his friends and the world around him, constantly replaying memories of Aunt May in his head. He may also feel a great sense of guilt, thinking that he could have done more to protect her.
She might also be proud. Peter is using his powers to help people, and Aunt May, being a kind - hearted person, would likely be proud of him for that. She could start to brag about him to her friends in a very discreet way, of course. And she would probably be more worried about him than ever, constantly thinking about all the risks he takes every time he goes out as Spider - Man.
Peter might be initially very nervous. He's been keeping this huge secret from Aunt May for a long time, and now that it's out, he's worried about how she'll react. He might stutter and struggle to find the right words to explain himself.
One great 'Peter Parker and Aunt May Fanfiction' is 'Aunt May's Wisdom'. It beautifully portrays the relationship between them. The story shows how Aunt May's words of wisdom always guide Peter in his life as Spider - Man. It's a heartwarming read that really delves into their bond.
I'm not sure of a specific 'Peter and Aunt May lemon fanfiction' title off the top of my head. But generally, these types of fanfictions often explore the deep emotional bond between them. Some might delve into alternate universes where Aunt May has a more active role in Peter's superheroics, like helping him with his suit or providing strategic advice.
Another theme is protection. Aunt May wants to protect Peter from the dangers of being a superhero, and Peter wants to protect her from the threats that come his way because of his powers. For example, in many fanfictions, there are scenes where Peter tries to keep his superhero activities a secret from Aunt May to keep her safe.
She might be shocked at first. After all, Spiderman is constantly in danger, and she has always seen Peter as a normal boy. So, it's a big revelation for her.
You can try fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you might be able to find some Peter and Aunt May - related ones there. Just be sure to use the search function effectively.
I'm not aware of any such fanfic. Fanfics often cover a wide range of themes, but this combination seems rather unusual and might not be a common one in the mainstream Spider - Man fanfic world.