Some fanfictions portray their relationship at university as a way to break free from the constraints of their past. In the original, they had a lot of baggage from their different natures (vampire and human). At university, they might be exploring new aspects of themselves and each other. For instance, they could be involved in different clubs or social activities that expose them to new friends and experiences, which in turn affects their relationship in a more positive and growth - oriented way.
In the fanfiction, their relationship might develop more quickly. They could be more open and honest about their feelings from the start, which is different from the original where there was a lot of hesitation and mystery.
In fanfiction, it often delves deeper into their emotions. For example, it might explore Edward's inner turmoil about his vampiric nature in relation to his love for Bella more intensively.
Often, it portrays their relationship as deeply passionate. They are usually shown to be completely in love and unable to keep their hands off each other in a very affectionate way, not just physically but also emotionally. Their eyes are always locked, and they keep whispering sweet nothings.
It often starts with attraction. Edward is drawn to Bella's unique scent and her differentness. Bella, on the other hand, is intrigued by Edward's mysterious nature.
Well, in fanfiction from Edward's POV, his relationship with Bella could be shown as more complex. For example, in the original book, their relationship was mainly about love and devotion. But in fanfiction, there could be added elements of tension. Perhaps Edward is more frustrated with Bella's decisions regarding their daughter. Also, the sexual aspect of their relationship might be explored more deeply in fanfiction, which was only hinted at in the original book. However, it's important to note that not all fanfiction will take this route.
It redefines it by making it unequal. Bella is in a position of being 'owned' in a sense, which is a huge change from their normal relationship where they are more like equals in love.
She might be more assertive. Since she is related to Klaus, she may inherit some of his confidence. So instead of being the meek Bella we know from the original, she could be more outspoken and take charge of situations.
The original story is more about the build - up of their relationship, while the mating fanfic may jump straight into the more intense and complex parts of their relationship regarding mating. It might also introduce new elements that were not as prominent in the original, like certain rituals or deeper emotional connections that are specific to the mating concept.
Well, it might become stronger as they face this new challenge together. They have to rely on each other more for support and decision - making regarding their baby.
Well, it becomes more platonic. There's no romantic tension between them like in the original. Instead, there could be a sense of loyalty and family - based love.