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.
In most of such fanfictions, they might create evidence like hidden past connections. For example, AFO could be secretly involved in Izuku Midoriya's (Deku) family history. Maybe he had a relationship with Deku's mother long ago, which led to Deku's birth. But it's all fictional speculation within the fanfiction world.
One common plot twist is that Deku discovers the truth about his father in a moment of great crisis. For example, when he's facing off against AFO in a big battle, AFO reveals the truth to him, which completely shakes Deku's world view.
Well, Bakugo might scoff at first. He'd probably think Batman is too brooding and not as straightforward as he likes his heroes. But then as he reads more of the fanfiction, he might grudgingly admit that Batman's detective skills are cool. Deku, on the other hand, would be super interested. He'd be analyzing every move Batman makes in the fanfiction, taking notes in his head about Batman's strategies and how they could be applied in his own hero work. Uraraka would be more focused on the relationships in the fanfiction. She'd be all 'aww' at the cute moments and feel for the characters when they're in trouble.
He should first realize that a gay story is just like any other story about people's lives. He could try to understand the feelings and experiences of the gay characters in the story. Maybe he could even learn something new about love and acceptance. If he has any questions or misunderstandings, he could do some research or talk to people who are more knowledgeable about the gay community.
He should also try to find out where she got the stories from. If it's from the internet, he may need to set up proper parental controls. He could explain to her that there are many positive and healthy types of literature she can engage with instead, like classic novels or educational books.
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.
Well, obviously Deku in two forms - the younger and the older version are the main characters. The younger Deku is the one who is still growing and learning, while the older Deku has more experience.
Well, it depends on how he 'came in'. If he just walked into a room you were in without knocking, it might be a simple lack of manners. In that case, you can just mention it casually like 'Hey, it's a bit rude to just come in without knocking'. But if it's in a more intrusive way, like invading your personal area or making you feel threatened, then you need to take more serious action. Notify your friend or an adult you trust right away, and don't be afraid to speak up about how it made you feel.
Another plot might involve the older Deku being from an alternate timeline. He shows the younger Deku different ways he could have developed his skills and relationships, which makes the younger Deku reevaluate his own path as a hero.