Vernon is likely a character within the Psychonauts universe. In the context of the Vernon Ghost Story, he's probably the central figure who has some sort of encounter or relationship with the ghosts.
Vernon could be anyone. Maybe he's an old man in the neighborhood who loves to share spooky tales from his youth. Or perhaps he's a young person who had a strange encounter and turned it into a ghost story. Without more context, it's hard to say exactly who he is.
Petunia could be a great addition. Her relationship with both Harry and Vernon adds a lot of complexity. She could be the mediator or the one causing more trouble between them, depending on the plot.
In some fanfiction, Uncle Vernon develops by becoming more accepting. For instance, he may start to see Harry not just as a freak but as a person with unique abilities that can be useful. He might begin to tolerate the wizarding world a bit more, especially if he realizes that Harry can use his magic to protect the family from certain threats.
In general, a first love story can be full of discovery. For Lee Hansol, it might have involved getting to know someone on a deeper level, sharing secrets, and experiencing the joys and pains of new love. Maybe there were shy glances, hand - holding, and a sense of excitement that comes with falling in love for the first time. But again, without knowing who this Lee Hansol is, it's all speculation.
Maybe Vernon is jealous of Harry's magical abilities. He might see Harry as a threat to his 'normal' family image. Also, Vernon has always been a bully at heart and Harry, being an easy target in his house, becomes the victim of his pent - up anger.
Maybe Dumbledore steps in at the last moment and takes Harry away from Vernon's house. He could use his powerful magic to protect Harry and remove him from that hostile environment.