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.
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.
In fanfiction, when Draco sees Harry's scars, it can be a very poignant moment in a romantic context. It might represent a moment of deep understanding. Draco, who has grown up in a different world than Harry, finally sees the physical evidence of all the pain and trauma Harry has endured. This could break down barriers between them, as Draco realizes that Harry is not just the 'chosen one' but a person who has suffered greatly. It can be the start of a new connection, one based on empathy and a new - found respect, which then could blossom into a romantic relationship.
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.
Well, it could be that Draco is initially shocked and maybe a bit remorseful when he sees Harry's scars. He might start to see Harry in a new light, realizing the hardships Harry has faced. This could lead to a change in their relationship, perhaps from enemies to something more complex like reluctant allies or even friends.
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.
He could be stunned. Draco has probably heard about Harry's scars but seeing them in person is a whole different thing. It might make him speechless for a moment.
One common theme is rivalry. Since Harry and Draco are often at odds in the original story, in these fanfics, the rivalry can be pushed to the point where Draco is so frustrated or defeated by Harry that he cries. Another theme is pride. Draco has a lot of pride, and when Harry shatters it in some way, it can lead to tears. For example, if Harry is better at something Draco values, like magic or popularity.
In the fanfiction 'The Lost Friendship', Harry makes Draco cry when he chooses his other friends over Draco in a crucial moment. Draco had always secretly hoped for a real friendship with Harry, and this rejection is too much for him. Also, 'The Harsh Truth' is a fic where Harry, in an attempt to make Draco see the error of his ways, tells him some brutally honest things that make Draco realize his own insecurities and he ends up crying.
One reason could be character development. For Draco, crying because of Harry can be a turning point. It can make him re - evaluate his relationship with Harry and his own actions. And for Harry, it can also be a moment of self - reflection. Maybe he realizes he's been too harsh or misjudged Draco. Plus, it gives the writers a chance to show different sides of these well - known characters in the Harry Potter universe.