It could also be out of jealousy or spite. In some fanfictions, Draco might be jealous of Hermione's intelligence or her relationships with others. By removing her memory, he could be trying to make her more dependent or to get revenge in a cruel way.
He might regret it because he finally understands that Hermione was the one who truly accepted him for who he was. In fanfiction, often there's a development where characters see beyond the surface. Draco, being from a family with certain expectations, may have found in Hermione someone who didn't care about his family's dark past or his initial snobbishness. When he cheats, he breaks that bond of acceptance, and then realizes how special it was. Additionally, he could be regretful because he sees Hermione move on and be happy without him, and he misses the relationship they had.
Maybe it's because of their different outlooks on life in the wizarding world. Hermione is very much about following the rules and using magic for good and knowledge, while Draco has been more influenced by the power - hungry and sometimes underhanded ways of his family. This could lead to constant arguments and ultimately a break - up.
One possible reason could be their different backgrounds. Draco is from a pure - blood wizarding family with traditional values, while Hermione is a Muggle - born witch. Their families might not fully accept each other, leading to constant stress and ultimately divorce in the fanfiction. Another reason could be differences in their career goals. Maybe Draco wants to focus on maintaining his family's status in the wizarding world, while Hermione is more interested in promoting Muggle - wizard relations and her own academic pursuits, causing a rift between them.
Another reason could be related to a spell or a magical effect. There might be a love - inducing spell or some kind of magic that made Draco act in this way towards Hermione. The neck kiss could be the first physical manifestation of this magically influenced attraction.
One possible plot reason could be a misunderstanding. Maybe Draco thinks Hermione has some information that she's not sharing and he ties her up to force her to talk. In some fanfictions, it could be part of a game or a dare within the magical world they inhabit. Another reason might be that Draco is being influenced by some dark magic or a curse that makes him act out of character and tie Hermione up.
One possible reason could be a conflict of values. Hermione is a strong advocate for justice and equality among wizards and non - wizards alike. Draco, on the other hand, was brought up in a family with pure - blood supremacist views. Hermione might run away from Draco in a fanfiction if she realizes that his views are unchangeable and they are fundamentally opposed to her own. For example, if Draco makes a derogatory comment about Muggle - borns in front of her, it could be the last straw and she decides to run away.
He might use magic spells. In the wizarding world, there could be spells specifically designed for memory modification or removal. Draco, being a skilled wizard, could have found or learned such a spell to carry out this act on Hermione.
One possible reason could be fear. Maybe Hermione is afraid of how Draco will react. Given their history in the wizarding world, with their houses being rivals at Hogwarts and different beliefs, she might think he'll reject her or the baby. Another reason could be to protect the baby. There could be some threats or dangerous situations in the wizarding world that she believes Draco's knowledge of the pregnancy would put the baby at risk. For example, there could be dark forces that target the children of powerful witches and wizards, and she wants to keep the baby's existence a secret to safeguard it.
One possible reason could be a moment of intense emotion. Maybe Draco is frustrated with Hermione's success or her constant opposition to his ideas in the wizarding world. It could also be a misinterpretation of feelings. For example, he might actually have some hidden admiration for her but doesn't know how to express it in a positive way, so it comes out as this aggressive action. Another aspect could be related to the overarching plot of the fanfiction world. Perhaps there's a power struggle or a mystery that involves both of them, and this physical act is a turning point in the story.
In the fanfiction, it could be related to family values. Draco comes from a family with certain beliefs about blood purity. Hermione being a Muggle - born might be seen as beneath him by his family's standards. So, Draco might abuse Hermione as a way to show his superiority based on those wrong family - instilled ideas.