It could be that Draco has done something to harm Harry's friends. Harry is very loyal to his friends, and if Draco does something to endanger or hurt them, like getting Hermione in trouble at Hogwarts, Harry would be deeply affected and might break down in tears.
Maybe Draco says some really mean and hurtful words to Harry. For example, he might make fun of Harry's family situation, like his parents' death or his relationship with the Dursleys. Words like that can be really cutting and could easily make Harry cry.
A possible reason could be that Harry is feeling the weight of his responsibilities. He has to constantly fight against Voldemort and protect the wizarding world. When Draco sees Harry cry because of this, it shows the toll it's taking on Harry. Another reason might be a personal loss. If Harry loses a friend or a mentor, Draco could witness his grief.
One reason could be to add drama and conflict to the story. Fanfiction writers often like to create complex situations to make the plot more interesting. Another reason might be to explore different aspects of the characters' personalities in a non - traditional way.
In fanfiction, their kiss might be a way to break free from the expectations placed on them. Harry is always seen as the hero and Draco as the villain's sidekick. By kissing, they are defying those roles and expectations. It could also be a way to gain power over each other in a different sense. Instead of the usual power struggle based on magic or family name, the kiss becomes a new form of power dynamic between them.
One reason could be love. Draco might have fallen deeply in love with Harry and his possessiveness is a way of showing his strong feelings. He doesn't want to lose Harry to anyone else.
At first, it would become more strained. Harry would likely be angry and hurt by Draco's actions that made him cry, so he might avoid Draco even more than before. He might also be more on guard around Draco, not trusting him at all.
In the 'harry rejects draco fanfiction', it could be due to the social divide between Gryffindor and Slytherin. Harry, as a Gryffindor, has been taught to distrust Slytherins. Draco's actions towards Harry's friends, like Hermione who is a Muggle - born, also contribute. Harry may reject Draco because he stands for the discrimination that Hermione has faced from Draco and his family.
In many fanfictions, when Draco sees Harry cry, it can be a really powerful moment. It might be a turning point in their relationship. Maybe Draco realizes that Harry is not just the 'Chosen One' but also a vulnerable person. This could lead to a new understanding between them, and Draco might start to see Harry in a different light, perhaps even developing feelings of empathy or something more complex.
One possible relationship is that of reluctant allies. Draco and Harry have their history of rivalry, but the Veela forces them to work together on the desk. Another could be that of begrudging respect. As they work on the project, they start to see the skills in each other. And the Veela could be like a mediator between them, using her charm to keep the peace.
Maybe in some fanfictions, Draco is driven by a sense of self - preservation. He might believe that Harry will eventually turn against him or the Slytherin house. He could think that by killing Harry, he can secure his own place at Hogwarts and in the wizarding community. Additionally, it could be part of a larger plot by Voldemort or his followers. If Draco is forced to join Voldemort's side, he may be given the task of killing Harry to prove his loyalty.
One reason could be revenge. Draco might feel that Harry has wronged him in some way throughout their years at Hogwarts, like getting him in trouble or making him look bad. So, he decides to kidnap Harry as a form of payback. Another reason is that Draco may be under the influence of his family. The Malfoys might see an opportunity to use Harry for their own gain, and Draco is just following their orders.