Deku might be completely shocked at first. Since Bakugou has always been so aggressive towards him, he would never expect such a confession. He might just stand there, mouth agape, not knowing what to say.
Some bullies might mock BTS fanfic. They could make fun of the fans who write or read it, thinking it's just some silly obsession. They might not understand the creativity and passion that goes into creating these fanfics.
Some bullies might mock or make fun of spiderman fanfic. They could see it as something only 'nerds' are into and use it as another reason to pick on fans. For example, they might laugh at the outlandish plot ideas or the 'geeky' passion of the fans.
He might cry a lot. Deku is very emotional, and being cheated on would be a very painful experience for him. He could also get angry, which is rare for him, but this situation would be so unjust that he might not be able to hold it in. He'd probably start to question his self - worth too, thinking that there was something wrong with him that made his partner cheat.
As of now, Deku is very much alive in the manga. The plot hasn't reached a point where he meets such a fate. Usually, main characters like Deku have significant story arcs and aren't easily killed off.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.
Deku might be initially shocked. He's used to Bakugou's aggression, but an actual injury is different. He could be in pain and disbelief at first. Then, he might try to downplay it, especially if he doesn't want to cause trouble for Bakugou, because Deku is generally a very forgiving character.
They're popular because they play on the idea of the members of BTS being in a difficult situation. Fans like to see how their idols would react to something like being wrongly accused of bullying. It gives a chance to explore different sides of their personalities.
One popular 'BTS Bullies React' fanfic might be 'The Change'. In this fanfic, the members of BTS react to a situation where they are wrongly perceived as bullies. It has an interesting plot that shows their shock and determination to clear their names. Another could be 'BTS Bullies React: The Hidden Truth' which delves into a mystery surrounding false accusations of bullying against them. It keeps you on the edge of your seat with its twists and turns.