Perhaps it's a matter of time - sensitivity. Fury might not be able to wait until after class. There could be a time - critical situation where Peter's powers are needed immediately.
One reason could be that Fury wants to test Peter's ability to handle sudden disruptions. By calling him in class, he can see how Peter reacts under pressure, whether he can quickly shift from a student role to a superhero role. Another aspect could be that the situation Fury is dealing with is related to Peter's school or someone in it. So he needs to get Peter involved right away without delay. Also, it could be a way to show Peter's importance in Fury's eyes, that even his studies can be interrupted for the greater good.
In fanfiction, Fury might call Peter in class because he has received intelligence that a threat is imminent near the school. Peter, as Spider - Man, is the best - suited person to protect the students and the school. Fury doesn't want to waste any time in getting Peter informed and ready. He might also believe that Peter can handle the situation without it affecting his academic performance too much in the long run. And this could be the start of a new adventure for Peter that involves both his superhero identity and his school life.
Peter could also be very nervous. He's still a young hero and being called by the Avengers in such a public setting like in class could make him feel self - conscious. He might stutter when he tries to answer their call and fumble with his things as he gets ready to leave. He'd be thinking about all the possible things they could need him for and whether he's really up to the task while also dealing with the eyes of his classmates on him.
Maybe Harry has had some secret interactions with Snape that the readers haven't known about yet. These interactions could have made Harry feel a father - like connection to Snape, and in the heat of the moment in potions class, he just blurts it out.
Well, in fanfiction, it could be that Fury has been observing Peter for a while and finally decides to recruit him for a special team. Calling him in class is a rather dramatic way to start this new chapter in Peter's life. Fury might see great potential in Peter, not just his powers but also his intelligence and quick - thinking ability. So he wants to get Peter involved right away, even if it means interrupting his class.
Perhaps it's his best friend who has some juicy gossip to share. But it's really bad timing as he's in class. His friend might not be aware of his class schedule.
It might be for educational purposes, such as studying different forms of creative writing.
Well, he might get in trouble with the teacher. Teachers usually don't like students getting phone calls during class. So, the teacher could take his phone away and give him a detention.
Perhaps they call Peter in class because they've discovered some sort of conspiracy that involves the school or someone in it. Peter, being a friendly neighborhood Spider - Man, has a good sense of what's normal and what's not in his neighborhood which includes the school. They might need his help to investigate something strange going on within the school walls.
Peter's life would change drastically. He would have access to S.H.I.E.L.D.'s vast network. He could get better training in combat and espionage, which would make him a more well - rounded superhero. Also, he might have to move to a more secure location, which could mean leaving his friends and normal life behind, at least to some extent.
Maybe he sees inaccuracies in the fanfiction about Sonic and his world, and the smirk is his reaction to that. For example, if the fanfiction misrepresents Sonic's speed or abilities, Shadow, who knows Sonic well, might smirk.
One reason could be that they want to enlist Naruto's help for a particular mission. Since he has unique abilities as a jinchuriki and has proven himself in many battles, they may think he's the best person for the job. Also, they might call him to clarify some misunderstandings. There could be rumors or false information about Naruto circulating in the village, and the council wants to get the truth from him directly.