One reason could be self - defense. If the guy was harassing or threatening the girl, she might fight back to protect herself.
Sometimes it could be a matter of principle. For example, if the guy was involved in something unethical like stealing or cheating and the girl witnessed it and tried to stop him. If he resisted, she might end up beating him up. It also depends on the girl's personality. If she is strong - willed and has a sense of justice, she won't let bad behavior go unchecked, even if it means getting physical with a guy.
One reason could be self - defense. If the boy was harassing or threatening the girl physically, she might fight back to protect herself. For example, if he was trying to force her to do something she didn't want to do.
Maybe the boy said something really offensive to the girl. For example, he made unkind remarks about her appearance or her abilities.
One reason could be better preparation. Just like in a test or a competition, if the girl has studied or practiced more, she can beat the guy. For example, if it's a spelling bee, the girl might have spent more time memorizing words.
In a neighborhood, a girl, Emma, noticed a guy, Ryan, being mean to an old lady. Emma was into martial arts. She stepped in between Ryan and the old lady. Ryan tried to shove Emma aside, but she blocked his move and delivered a series of punches and kicks. Ryan ended up on the ground. Emma's actions made her a hero in the neighborhood and taught Ryan not to be so unkind.
Well, they are not extremely common but can happen. Sometimes, it could be in self - defense. If a man is harassing or threatening a girl, she might fight back. For example, if a girl is being followed in a dark alley by a man making lewd comments and she feels in danger, she may use force to protect herself.
One reason could be for a performance, like in a play or a movie. Acting often requires actors to step into different genders to bring a story to life. Another reason might be for a prank or a dare, just for fun among friends. Sometimes, it could also be for a social experiment, to see how people react to someone breaking gender norms.
One reason could be for a performance like in a play or a musical. For example, in some classic plays, there are female roles that are so iconic and require a certain acting skill, so a guy might dress as a girl to bring that character to life. Another reason could be for a prank or a joke among friends. They might want to see how the guy looks like as a girl and have some laughs.
One reason could be that the big brother took something that belonged to the little sister, like her toys or snacks. So she got angry and decided to take matters into her own hands.
He might be looking at the other girl simply because she is in his line of sight while he is lost in his own thoughts. It doesn't necessarily mean he has any particular interest in her. For example, he could be waiting for someone in a public place and his eyes just happen to land on her while his mind is wandering.
One possible reason could be envy. Flash might be jealous of Peter's intelligence or popularity at school. Maybe he feels overshadowed by Peter and his achievements, so in the fanfiction, his anger and frustration lead him to lash out physically.