Another ending could be that the trick goes on for a long time. Naruto gets really hurt and starts to distance himself from both Sasuke and Sakura. Sakura, on the other hand, finally realizes what Sasuke is doing and she decides to leave Sasuke. In the end, Sasuke is left alone, regretting his actions, and Naruto has to heal from the emotional damage on his own.
I haven't actually read this specific fanfic. But generally, if Sasuke is using Sakura to trick Naruto, it could be a very complex and somewhat devious plot. It might involve Sasuke's long - standing issues with Naruto, perhaps some jealousy or a need to gain an upper hand in their relationship. And using Sakura, who has her own feelings for both of them, adds another layer of drama.
In a fanfic, it could be for comedic purposes as well. The idea of Sasuke trying to act like Sakura while tricking Naruto can lead to some really funny situations. Maybe Sasuke is forced into this by some strange situation or magic. And he has to keep up the act of being Sakura, which includes mimicking her mannerisms and speech patterns, all while trying to fool Naruto. This could create a lot of humorous misunderstandings and interactions within the story.
I'm not sure of a specific fanfic with that exact plot, but you can try searching on fanfic platforms like FanFiction.net or Archive of Our Own. Use keywords like 'Sasuke transforms into Sakura, Naruto' to narrow down your search.
One possible reason could be that Sakura has finally grown tired of Sasuke's aloof and cold behavior towards her. She might have realized that she has been constantly chasing after him while getting little in return, so she decides to ignore him as a form of self - preservation.
In proper fanfics rather than 'lemon' ones (as 'lemon' implies inappropriate content), Naruto is known for his never - give - up attitude. He's the heart of the story, always trying to bring Sasuke back and protect his friends. Sasuke is a complex character, with his family's past haunting him, which makes him seek power and revenge at times. Sakura, she starts as a girl with a crush but evolves into a capable ninja. These characteristics are often the foundation for fanfic authors to create interesting stories that don't involve improper content.
Some fanfic authors might write it as a form of wish - fulfillment. They might prefer the Naruto - Sakura relationship more than the Sasuke - Sakura one. So, they create a scenario where Sakura turns to Naruto in a romantic way. Additionally, it could be a way to explore the characters' personalities further. For example, how Sasuke would handle being betrayed and how Naruto would deal with being involved in such a situation. It gives a chance to dig deeper into their emotional and moral aspects.
In such a fanfic, one possible reason could be Naruto's feeling of being left out. Maybe he sees Sakura's constant focus on Sasuke and feels neglected in their friendship triangle. Another reason might be jealousy. If Naruto has unrequited feelings for Sakura, seeing her love for Sasuke could turn to hatred over time.
Sasuke could initially be a vampire who is full of anger and resentment, maybe because of how he was turned. But Sakura's positive attitude and kindness could start to soften him. He might start to open up about his past and his feelings. Sakura could develop from a somewhat naive vampire into a more worldly and wise one. She would learn about the darker side of the vampire world through Sasuke, and this would change her. Maybe she would become more cynical at first, but then find a balance between her old self and the new knowledge she has gained.
For Sakura, she could grow in terms of her leadership skills. If they encounter any difficulties in the forest like being chased by a group of wild animals or getting caught in a dangerous situation, she could step up and lead the way out. Sasuke might then realize that Sakura has the potential to be a great leader. And for Sasuke himself, he could become more open to the idea of a relationship with Sakura. The seclusion of the forest could provide the perfect backdrop for him to explore his feelings for her.
One possible plot could be about them adjusting to family life. Naruto and Sasuke might have to learn how to be good fathers, while Sakura adapts to being a mother. There could be challenges like dealing with the expectations of the village. Another aspect could be the family facing external threats together and growing stronger as a unit.