Their personal feelings towards each other could also play a role. Leah might have felt that Jacob was getting special treatment within the pack. Jacob, in his eyes, might have seen Leah as too moody or difficult. So when they clashed, insults became a way to vent their frustrations. For instance, Leah could have said something like 'You think you're so great just because you're the alpha' and Jacob could respond with 'You're just a bitter person' or something similar.
One possible story could be that after Jacob gets over his long - held feelings for Bella. He starts to notice Leah in a new light. Maybe during a time when the pack is facing a great danger and they have to rely on each other more than ever. In that moment of shared vulnerability and trust, they might share a kiss.
I'm not entirely sure as the 'grunt story' isn't a widely known mainstream narrative. But generally, Leah Clearwater and Jacob Black are characters from the Twilight series. Leah is a werewolf and has her own complex relationships within the werewolf pack. Jacob has his own story arcs involving his love for Bella and his role in the werewolf community. Maybe in this 'grunt story' there could be some specific adventures or interactions between them that are unique to this particular telling.
I'm not sure specifically which story you are referring to regarding Leah Clearwater and Jacob Black's insult. There could be various fan - made or canon - related incidents in the Twilight - related lore. Maybe it was a situation where they were in an argument about the pack or some personal matters within their werewolf community.
One reason could be the shared bond of being part of the Quileute tribe. They understand the unique challenges and responsibilities that come with it. Also, they both have had difficult experiences in love. Jacob was pining after Bella for a long time, and Leah had her own heartbreaks. This mutual understanding of unrequited love might draw them together in a moment of closeness.
If they were mates, it would be a very different 'Twilight' story. Jacob would have to balance his loyalty to the pack with his new relationship with Leah. Leah, being a strong - willed character, would likely demand equal respect in the relationship. They might face challenges from the pack, as Leah has had some tensions within it. And their relationship could change the dynamics between the werewolves and the Cullens, as Jacob's previous connection to the Cullens was mainly through his relationship with Renesmee.
Leah Clearwater is jealous mainly because she has deep-rooted feelings for Jacob Black. When Jacob shows interest in other girls, especially Bella, it makes her feel left out and unloved. As for Jacob, his jealousy is related to his pride. He doesn't like to see Leah getting cozy with other werewolves. He thinks of her as someone in his 'territory' in a sense. Also, the competition for leadership in the pack can fuel his jealousy towards Leah when she seems to gain more influence.
Well, it could be about their playful banter in the werewolf pack. Maybe they tease each other about their hunting skills or who can run faster in wolf form.
Maybe it's because of a love triangle situation. If they both have feelings for the same person or there are complex romantic relationships involved that are causing jealousy and possessiveness. This can easily stir up anger as emotions run high in such cases.
One possible reason could be territorial disputes. In their world, there might be areas that both Jacob and Leah consider their own or important to their packs. If one encroaches on the other's territory, it can lead to anger.
The heartbreak in Jacob Black and Leah Clearwater's story is mainly due to unrequited love. Jacob was in love with Bella, but Bella chose Edward. Meanwhile, Leah had her own heartaches. She was imprinted on by Sam, who then left her for her cousin Emily. This led to a lot of pain and a sense of being left out for both of them.