When Lily Jacobs was born, she inherited Fazire - a genie. Her family had three wishes and they'd only ever used one so Fazire was stuck in the human world. This worked since he'd become a member of the family anyway.
Even with a genie, Lily's young life wasn't perfect. To escape the kids making her miserable at school, Lily buried herself in romance novels. One day, when the teasing was just too much, she used one of her wishes. She told Fazire she wanted to find a man like in her books and she made the most complicated wish Fazire had ever heard. Her wished-for man had to be impossibly handsome, virile, fierce, rugged, and ruthless (amongst a dozen other things).
He also had to think she was beautiful and he had to love her more than anything in the world.
Nathaniel McAllister wasn't born to a life where there were such things as genies granting wishes. His life was filled with drugs, crime, and neglect. He was running errands for a gangster before he was in his teens and, even though life and hard work led him to wealth and respectability, he always knew, deep down, he was dirty. When Nate met Lily he knew he was no good for her but as virile, fierce, rugged, and ruthless as he was, Nate was no match for the pull of sweet, innocent Lily.
Unfortunately, Lily's wish included that she and her hero go through trials and tribulations to test their love. And Fazire wasn't only a good genie, he loved Lily - so he gave her exactly what she wanted.