Another reason could be that Jiraiya has some doubts about Naruto's readiness or potential. He might think that Naruto is not yet at the level where he can fully benefit from Jiraiya's training. For example, Naruto may lack some basic skills or knowledge that Jiraiya believes are necessary prerequisites for his more advanced training.
It could also be that Jiraiya is facing some personal issues. Perhaps he has some inner demons or unresolved problems from his past that are currently affecting his ability or willingness to take on a new student. He might be in a state of self - reflection and not ready to commit to training Naruto.
Perhaps Jiraiya has some personal issues or inner conflicts. He might be dealing with his own past traumas or demons that prevent him from taking on the role of Naruto's trainer. For example, he could be haunted by the failures in his previous relationships or battles, and he feels unfit to train Naruto until he sorts out his own problems.
One possible reason could be that Naruto feels he has learned all he can from Jiraiya at that point. Maybe he has reached a level in his training where he believes he needs new experiences and challenges that Jiraiya can no longer provide.
One possible reason could be that in this fanfiction, Jiraiya might be preoccupied with other important matters. Maybe he has a secret mission that demands his full attention and he simply doesn't have the time to train Naruto. Another reason could be that there is some sort of conflict or misunderstanding between them that prevents Jiraiya from taking Naruto under his wing. For example, Naruto might have unknowingly offended Jiraiya in some way, or there could be a prophecy or external force that is keeping them apart for the time being.
One possible reason could be that Kakashi might be haunted by his past experiences. He has lost many comrades, and perhaps he's afraid that getting too close to Naruto and training him would put Naruto in danger as well. He might think that Naruto, being the Jinchuriki of the Nine - Tails, already has a target on his back, and training him would only make that target bigger.
One possible reason could be that Naruto might feel he doesn't fit in with the members of Team 7. Maybe he has some personal goals that he thinks he can't achieve while being on the team. For example, he might want to focus more on individual training to become stronger in a specific area like mastering a certain jutsu, and he believes being on a team would be a distraction.
One possible reason could be that Naruto is too focused on his ninja duties. He has always been dedicated to protecting the village and his friends, and marriage might seem like a distraction from that. For example, he has to constantly be on guard against new threats and train the next generation of ninjas.
One possible reason could be that Naruto might feel Jiraiya is being too overbearing in his training methods. In some fanfictions, Jiraiya might push Naruto too hard without considering his emotional state, leading to Naruto snapping.
Naruto might be initially very disappointed. He has always looked up to Jiraiya and expected to be trained by him. So, when faced with the refusal, he could be heartbroken and feel like he has lost a great opportunity.
One possible reason could be that in the fanfic, Jiraiya might have made a decision that Naruto strongly disagreed with, like leaving him alone at a crucial time for a long mission. This could make Naruto feel abandoned and thus start to hate him.
One possible reason could be that Jiraiya was trying to test Naruto's survival skills. He might have thought that by pushing Naruto off the cliff, Naruto would be forced to use his ninja skills in a real - life - or - die situation and grow stronger as a result.