The Unforgivable Sin and it's Effects

It's a fan fiction about y/n and her boyfriend Natsu who cheated on her with Lucy. What happens when he starts to feel something for y/n? What if it's too late and Gray is with her instead? What if y/n ends up alone without either of them because of her stubbornness?

It is my first x reader story. It is also my first story ever on this.