Maybe in the fanfiction, they discover a shared interest in art or music that deepens their bond. Since Laurent has a more refined and old - world charm, he could introduce Bella to a whole new world of cultural things, which in turn makes their relationship more complex and interesting.
One idea could be that they have to overcome the differences between their two worlds. Bella being from her normal human world and Laurent from his vampire one. They might struggle with how their relationship is seen by others, like the Cullens.
There could be other vampires too. Maybe some of Laurent's old friends or enemies. His friends could try to help him and Bella, while his enemies could try to use Bella as a way to get to Laurent. All these characters would contribute to the overall story and the development of Bella and Laurent's relationship.
Well, perhaps the story could start with Bella moving to the area where the Denali sisters live. At first, there's tension and misunderstandings between them. But as time passes, they realize they are mates. Then, a new vampire arrives in town who has a vendetta against the Denali sisters. Bella, with her unique human perspective and courage, helps the sisters face this threat. They also have to deal with the reactions of the local vampire community who are not used to such a unique mating situation.
One idea could be that Jasper and Bella discover a unique bond that helps them face the challenges in the vampire - human world together. For example, Bella's unique ability to resist vampire powers in the original story could be enhanced when combined with Jasper's gift of manipulating emotions.
One idea could be that they meet in a completely unexpected place, like a small European town during a music festival. Bella is there to experience new things after the events in her own story, and Peter is there to escape his past. Their initial encounter is full of tension as they sense something different about each other. Another plot could involve them having to work together to solve a mystery that involves both the vampire and human worlds. Maybe a new type of vampire is emerging that threatens both, and they must combine their unique skills and knowledge to stop it.
One idea could be that Laurent tries to redeem himself in Irina's eyes. Maybe he saves her from a dangerous situation, like a group of rogue vampires. This would start to change her view of him from being just a somewhat untrustworthy vampire to someone she could potentially care about.
One plot idea could be the internal struggle they face within the vampire community. Since vampires usually have a monogamous mate concept, the three of them being mates would be a huge deviation. They might have to deal with the judgment and envy of other vampires. Another idea is exploring how they protect each other from outside threats. For example, a new vampire coven that doesn't accept their unusual relationship might try to harm them. And also, their daily life together could be full of interesting moments like sharing their different experiences from their long vampire lives.
In some 'bella and james mates fanfiction', a plot twist could be that James is actually under a spell that makes him seem evil, and when the spell is broken, he and Bella can truly explore their mate bond. This completely changes the dynamic from the original story.
One possible plot line could be Leah and Bella initially having a rocky start as mates due to their different personalities and past experiences. For example, Leah's tough exterior might clash with Bella's more reserved nature. Another could be them facing challenges from the werewolf and vampire communities as their relationship is something that goes against the norms in their world. They might have to prove that their bond is strong enough to withstand all the opposition.
Perhaps they go on a journey to find out more about their relationship's origin. They might travel to different vampire clans around the world to seek answers, facing all kinds of adventures and challenges along the way, and in the process, their bond grows even stronger.
One interesting plot twist could be that their soul - mate bond is revealed to have a special power. Maybe it can temporarily nullify Jasper's ability to sense emotions when they touch. This would be a huge change in the way he interacts with the world and with Bella.