Since this book is set in England, let me use a British word to describe it. Treacly.
I had a boyfriend in high school, but I don't remember our relationship being like this, with SO MANY FEELS. I kept reading so that I could see whatever stupid resolution it was going to come to. And it was overwrought and ridiculous like the rest of this book.
I liked the kids, honestly. If it could just be a book with the kids and no squicky subject matter I think I would enjoy it. Perhaps throw them in a steampunk dystopia? Now THAT I would read.