"Lamb" is a 2011 book by Bonnie Nadzam, and <a 2015 film> by Ross Partridge.
It features the mid-40s David, whose childless marriage is over because of his affair with 20-something Linny. Their relationship is built on sex, but he doesn't like her all that much. An 11-year-old girl "Tommie" approaches David on a dare to ask for a cigarette. Something in her situation intrigues him, and he proposes a pretend abduction. She doesn't agree to it, but gets abducted anyway, to teach her a lesson. He just takes her to her home. Home for Tommie is a dreary place, with an exhausted mother and her critical boyfriend. She gets very little attention. Her clothing is ragged. When she comes in late, she's told in a weary voice that she shouldn't come in after dark, but the subject is instantly dropped. Neglect.
Despite having been kidnapped, Tommie comes back to the same place the next day, as does David -- who when asked introduces himself as Gary. He buys her a fast food lunch, and they meet to talk things over a couple times.
This could be the opening for a classic tale of grooming and child sexual abuse. She's starved for attention and not closely supervised. He takes an interest in her and she soaks it up, open as all children are to diverse experience. The classic grooming tale would be cynical from the start, with the man having his eye on sex and nothing else. The more subtle grooming tale would be genuine affection, but sexual desire not far in the background and coming to the fore -- as it will for most of us when in close quarters with people we are attracted to.
At the other extreme, it could be the tale of a mentor who enriches a girl's life, at all times sensitive to what she needs. (A relationship that starts with a kidnapping would not fit this pattern, however!)
"Lamb" is in the middle, because there is never any sexual activity between them. Yet he loves her in an obsessive and unhealthy way. I tag him as a non-exclusive pedophile. He's spent his life in relationships with women, but Tommie tugs at his heart in a way that you sense no one before has. And the moral I take away from the story is how easy it is for a man to emotionally mess with an underage girl without really meaning to -- even without any sex. Gary is very self-involved, and while he wants to give to Tommie and help her, it's all within his own worldview -- his own emotional morass. He recognizes this at times, and compounds the problem by telling her what a bad person he is, and how if she comes to hate him he should track him down and beat him senseless.
It's true that the world has plenty of Garys who are attracted to adults and lay on them exactly what he lays on Tommie. Most adults have the knowledge and backbone to deal with this. Tommie doesn't -- few 11-year-olds do. She comes to have intense feelings about him, as is inevitable towards someone giving her so much attention and such a different set of life experiences. She labels it "love" at some points, but it's really hard for her (or us) to know what kind of love it is. There's no hint that she wants to make it sexual.
The setting for most of the story is a trip they take from Chicago out to his late father's run-down house in rural Colorado. They both know that they would never get her mother's permission, so this will be seen by the world as a kidnapping. He promises her she can change her mind any time and he'll take her home. At a number of points she does ask to go home, but each time he talks to her, soothes her, asks her to forgive him, and they go on. (The story is complicated by Linny's arrival unannounced in Colorado, where Gary/David manage to hide Tommie for a few days, but this is just a distraction from the important lessons of the book.)
Although "Lamb" is fiction, you suspect Bonnie Nadzam experienced some tamer version of this herself. As a realistic story it is very interesting as it bears on the question of "youth liberation". Youth liberation would say 11-year-old Tommie should be free to go off with Gary if she wants. She would not even have to tell her mother where she's going or consult with her, so it would not be kidnapping. She might well want to go with him, because her home life is so emotionally barren. She would have no obligation to go to school, so she would be free to remain with Gary in Colorado indefinitely. But she is emotionally at his mercy. She could spend years there without getting the strength to break away, and it would damage her immensely. In our real world, the law serves a vital purpose -- Gary does eventually drop Tommie off at home after a few weeks away. She has the impulse to just stay away forever, not wanting to face the inquisition she'll face at home. Under youth liberation there need be no police involvement, but the emotional disruption would still be intense. In our real world, I see her recovering under the dull, boring influence of her mother -- who does put food on the table and give her a roof over her head. She has a chance to get through a barren childhood and blossom on her own at age 16 or 18.
Gary doesn't even intend to harm anyone. The possibilities for men who lack any conscience are frightening. Under youth liberation, a man can kidnap a girl and later claim she agreed to go with him. It's her word against his, and the standard of reasonable doubt would make it hard to get a conviction.
It's true that there are abusive parents, and kids suffer under them. We could write a story with Tommie being abused by her mother's boyfriend, and Gary being her true savior. But it would be a much rarer story. What's the proportion of goodhearted avuncular men to those who are emotionally or sexually obsessed with girls like Tommie? More to the point, what's the proportion who would take an interest in a Tommie asking for a cigarette? Human history and even our underlying mammalian biology suggest that parents are in the best position to serve the interests of their children.
Many pedophiles in online forums such as GirlChat or BoyChat posit as their ideal the non-sexual relationship with a "young friend". Although I believe the law is too blunt an instrument to properly intervene in non-sexual friendships between men and children, "Lamb" shows the emotional dangers. Men present themselves as infinitely sensitive to the needs and wishes of the child, always putting him or her first. Maybe a few do. But experience between adults suggests that people who feel romantic and sexual passion are not typically good judges of what's good for someone else. Adults have a fighting chance of sticking up for themselves and getting out of abusive relationships. Children have far less. Even more important is that despite the risks, love/sex relationships are vital to the happiness of adults. They are not important to children at all.
I highly recommend "Lamb" in both its book and movie versions.