Perhaps 'y' is a relative of Harry's that was thought to be dead. This relative could have a unique magical heritage that they pass on to Harry, making him even more powerful. For example, if 'y' was a distant cousin from a line of powerful seers, Harry might develop some precognitive abilities.
One possible reason could be miscommunication. Maybe Ginny feels neglected by Harry because he's so caught up in his own heroic deeds and doesn't pay enough attention to her. So she might seek comfort or excitement elsewhere.
The 'futa' concept is often inappropriate. However, there are many great normal Harry and Ginny fanfictions. For example, some focus on their post - Hogwarts life, like how they deal with the challenges of the wizarding world together. You can find these on well - known fanfiction websites by using appropriate search terms like 'Harry and Ginny post - Hogwarts' or 'Harry and Ginny relationship development'.
In fanfiction, anything can happen. However, if Ginny cheats on Harry, it would likely shatter the trust in their relationship. It could lead to a downward spiral in the story, with Harry feeling betrayed and perhaps seeking revenge or just distancing himself. This could also change the dynamic among their friends and family, as everyone would be caught in the middle of this drama.
One possible reason could be that Harry is too focused on his fight against Voldemort and doesn't want to put Ginny in danger. He might think that being with her would make her a target for his enemies.
Hermione would be a great addition. She could be the one who accidentally discovers their secret and then has to decide whether to keep it or tell Ron. Neville could also be involved. Maybe he stumbles upon them in the greenhouse while they're having a secret moment and he becomes their accomplice in keeping the secret.
The relationship can be shown as one of deep trust. Ginny feeling comfortable enough to fall asleep on Harry indicates she trusts him completely. It could also show a sense of intimacy, like they are in a very close and personal space.
Well, it could be that Harry has started acting really distant from Ginny. He might be canceling their dates frequently or not being as affectionate as he used to be. In the fanfiction, Ginny might also find some strange gifts or notes that she suspects are from another girl to Harry, which makes her think he's cheating.