Some paedophiles say they would never abuse children. But what support is there for people like this and how should society treat them to prevent abuse happening?
Warning: Due to the subject matter, there are disturbing details in this article.
Adam messaged a few days before we were due to meet for the first time.
I'll let you know what colour top i'm wearing or something so you can recognise me. Although I'll just be the creepy looking guy :D lol.
It was the kind of place that would be packed full of people enjoying two-for-one cocktails on Saturday nights, but Adam just wanted tap water.
He was clearly nervous.
In his early 20s, but he could pass for younger. Slight and fresh-faced. Brown hair, clear skin and softly spoken. Not "creepy looking" at all.
He describes himself as "normal" and says he likes to hang out with friends, go travelling and play video games. On the surface, it's hard to argue with his self-description.
But he has a secret.
"Adam" isn't his real name. He didn't want us to use that, though he insists he's never done anything illegal.
But he is a paedophile.
That term is widely used today. It's used interchangeably with child sex abuser by the public - you can find it in many news reports describing the actions of molesters.
But academics use the term differently. In the DSM-5, the manual issued by the American Psychiatric Association, and used by psychiatrists across the world, paedophilia is listed as a "paraphilic disorder".
Effectively, it is defined as a form of mental health condition where an adult has a primary sexual attraction to pre-pubescent children.
It doesn't mean that they have abused children, and in fact, psychiatrists and criminologists believe that not all child abusers are paedophiles. Many are motivated by a desire for power or control.
People like Adam refer to themselves as "anti-contact" paedophiles. They recognise their own attraction to children but understand that is wrong to abuse them.
Adam first realised that there was something different about him when he was 13. His friends suddenly started talking about girls and he just wasn't interested.
He couldn't reveal the truth. He didn't think about girls at all, but about boys who were younger than him.
At that stage, the age gap wasn't dramatic, just a few years.
"As I got older, the age stayed the same and got even younger really."
Adam spent the next few years doing what almost every teenager does - trying to fit in.
When he describes this period, his words come out in a rush. "I felt isolated. I tried to hide it, just tried to ignore it, pretend it wasn't there, pretend I was normal, concentrate on my schoolwork, concentrate on playing football."
Deciding to lie, he pretended to like a girl in his class. Adam knew enough to pick someone who was considered pretty. As he was so shy, no-one really questioned why he didn't ever ask her or anybody else on a date.
But Adam wasn't yet at a point where he thought of himself as a paedophile.
"I thought I was too young, really. I thought paedophiles were old men who looked at children."
This has elements of truth in it. The APA says only people aged 16 or older can be classified as paedophiles. There must also be an age gap of five years or more between the subject and the children they are attracted to.
Prof Derek Perkins is a consultant forensic psychologist and has set up treatment programmes for sexual offenders.
"It's a recognised mental disorder and it's something that people don't choose to have. It's a condition in the same way that someone might have depression or ADHD.
"A lot of people are able to manage it without acting on it."
By the time Adam got to 17, he'd spent four years trying to ignore his feelings about children. Realising this wasn't something he would grow out of, he decided to try to "solve it".
When he talks about this time in his life, the word he uses most is "scared".
The other word that comes back is "normal". He repeats it as he explains that he had always wanted to have a wife and children one day.
But something made him realise this just wasn't possible.
"I got really worried that I'd end up hurting a child and go to prison. My life would be over."
There's a growing body of research into young paedophiles like him, including those who have never been through the legal system.
People like Adam have started to form online forums and chat groups where they discuss their struggle.
Many of them, including Adam, dislike the word "paedophile" because of the way the media uses it interchangeably with "child rapist" or "child abuser".
Instead, he refers to himself as an "MAP", which stands for "minor-attracted person".
Adam seems likeable on the surface. It would be easy to assume he is merely manipulative, trying to project a nice-guy image. I can't speak to his innermost motivation, but I don't think that's the case.
When we first met, I asked him to show me photo ID to prove his real name and age. The picture was a few years old, and he had a dodgy haircut. He was able to tease himself for how outdated it looked.
He is invariably polite and keen to highlight his intelligence. He mentions that he went to a good university and talks about compliments from his boss.
But it's clear he is not a naturally confident person and doesn't find it comfortable speaking to a journalist. He even gets nervous about dealing with public transport.
I should say now I am very introverted etc, so at least half the problem isn't me actually trusting you, it's me actually having the courage to meet a stranger to talk to.
Was he ever tempted to act on his attraction during puberty?
"I was too shy to do anything, anyway, with anyone. Even if I wasn't a paedophile."
Adam wants to speak to out, he says, because he wants to protect children.
He explains that he gets "so upset" when he sees stories about child abuse on the news: "I'm doing this so that some people will stop that."
Adam is very firm on this point. He says he has never abused a child, either online or in person.
He doesn't even wait until the end of the question before replying emphatically: "I would never. I'd never do that."
There's not an ounce of hesitation. He sits upright and doesn't slouch or fidget. He says he would kill himself before hurting a child.
And yet when he is asked about the precise nature of his attraction, he starts to become uncomfortable.
He squirms, stammers and clams up. He can't get the words out and the conversation moves on.
He admits to having "crushes" on young boys but he says he works hard to distract himself.
In a message, Adam explains his "age of attraction".
Sorry for not being able to answer when you asked the ages, it's something I was dreading you asking … I hope you understand. My aoa is 1-15, but the emotional side is a lot stronger than the physical side with the lower ages.
In person, he uses almost the exact same phrase.
"My age of attraction is one to 15 but as they get younger the emotional attraction is more prominent."
He picks his words carefully, pausing before speaking.
By this stage, I had built up a relationship with him. He had opened up about the isolation of his teenage years and his firm resolve to never abuse children.
It's difficult to hear him talking about an attraction for very young children.
"I don't really think of a toddler in much of a sexual way, but rather, I want to cuddle one and make sure they're happy. That is mainly it with younger children."
It's hard to avoid being unsettled by this - and that sense of what is not being said, especially with the qualifiers "much of a sexual way" and "mainly it".
He tries to clarify: "If you're a parent and you have a toddler, you cuddle them, kiss them, make sure they're fed and safe and happy. And that's kind of the same feeling, but I just get it with all children. Or boys."
But most people want to make sure children are safe and happy.
After a slight hesitation, he replies that there is obviously "some slight attraction" but that it is drowned out by his emotional response.
There's some debate about the numbers, but it's estimated that between 1% and 5% of men have some form of sexual interest in children.
There do exist a small number of female sex offenders, but it is unknown how many of them might be genuine paedophiles. Although there clearly are women who molest children, a large proportion do so in conjunction with a male offender.
Some paedophiles are exclusively attracted to children. Others are also drawn to adults and have "normal" relationships with their peers.
Adam wishes he was attracted to adults but he just isn't.
What has made him like this?
It was long thought that paedophiles had typically been abused or had a traumatic event in their own childhoods.
But Canadian clinical psychologist James Cantor argues that paedophilia is down to "cross-wiring" in the brain.
He looked at MRI scans of paedophiles and found that they had less white matter, which links parts of the brain together.
Cantor thinks the key is how the brain is formed in the early stages of pregnancy.
"The dream is to prevent it before the paedophile is even born."
Despite his dedication to avoiding contact with children, there was a period when Adam wavered.
At about the age of 18, Adam came across "pro-contact" paedophiles online. They told him that "having sexual contact with children is OK, that there's nothing wrong with it and that it doesn't harm the child".
He wanted to believe them.
Clearly uncomfortable talking about this period in his life, he sits still, his fingers rubbing together nervously.
I ask if he thought he might end up abusing a child.
He admits: "I thought maybe at some point in my life, maybe I would. Not imminently. But I realised, hey this actually hurts children and I don't want to be part of this."
But did he view illegal images of children online?
He says that he hasn't. Partly because he wasn't "tech savvy" enough to know how to avoid getting caught.
That seems a strange explanation.
But later, he messages with more context.
I guess I wanted to look due to curiosity. I think maybe deep down I knew it was wrong (being pro contact) but I kind of just made myself believe it was ok because I didn't want to be sad and alone for the rest of my life. I guess that's why I didn't follow through or try harder to look, because deep down I knew it was wrong but on the surface I convinced myself it was ok.
Other "anti-contact" paedophiles tell me they went through similar phases where they thought they would end up offending. One described himself as "a ticking time bomb".
Adam says he has never blamed himself.
"I didn't choose it. I got unlucky in life. I've never been horrible to anyone, so why has this horrible thing happened to me?"
He says that he was suicidal during that time, but that the feeling is much rarer now.
He broke away from the "pro-contact" paedophiles after doing more research, and he says he couldn't possibly get any pleasure from looking at illegal images of children. Adam resolved never to abuse a child.
If you are affected by the issues raised in this piece, the following organisations can help:
StopSO (the Specialist Treatment Organisation for the Prevention of Sexual Offending) can work with people who are worried about their sexual thoughts.
The NSPCC specialises in child protection.
The National Association for People Abused in Childhood offers support, advice and guidance to adult survivors of any form of childhood abuse.
Childline is a private and confidential service for children and young people up to the age of 19.
The Children's Society works to support vulnerable children in England and Wales.
Jake - again not his real name - is another "anti-contact" paedophile. He's a year or so younger than Adam, and their stories are remarkably similar.
Jake also realised during puberty that he was attracted to younger children - girls aged 5-11.
He's also attracted to women his own age. It's not quite as powerful as his feelings towards children, but it gives him hope for his future.
Like Adam, he wouldn't stand out in a crowd. He is handsome enough for people to wonder why he is always single. But he is also shy.
For our entire conversation, he sits almost totally still with his arms hugged around his body. It doesn't come across as rude - more like he's physically steeling himself for an ordeal.
He says the hardest part of being a paedophile is knowing that he is "one of these people that everyone hates".
But he's clear in his resolve to never abuse children.
"I still have morals. I still know what's good and what's bad. I'm not going to hurt someone like that just to make myself feel better."
Like Adam, he went through a period when he couldn't stop his mind "justifying things that weren't really justifiable".
So even though he says he was firmly against sexual contact, he decided that "romantic relationships" with 11-year-old girls would be acceptable. But he's fuzzy on what he meant by that - only going so far as to mention "dates and stuff."
But he insists he didn't ever act on those thoughts.
At one stage, he thought about going to his GP for help, but decided against it. Despite doctor/patient confidentiality, medics and other professionals have a duty to tell authorities if they think a child has been, or could be, harmed.
"I realised how risky it was. You never really know if they're going to want to report you if they feel like you're a danger."
He felt that his paedophilia was under enough control for him not to pose a threat to any children, but he knew his doctor might not believe him.
If he had been able to get professional help, it would have made a big difference, he suggests.
"I wouldn't have gone down kind of the route I did of deluding myself into thinking certain things."
This is something that many of the experts agree with. Prof Derek Perkins says there might be no magic cure for paedophilia, but he is adamant that treatment helps.
And that treatment isn't just about helping paedophiles cope with their attraction to children.
The primary aim is to reduce the possibility of child sexual abuse.
"From a child protection point of view, the more help that can be provided as early as possible, the better."
Tom Squire, clinical manager of the Lucy Faithfull Foundation, says there isn't enough support.
The charity aims to prevent child sexual abuse by working to stop would-be sexual offenders committing a crime in the first place. It runs the Stop It Now helpline.
It takes calls from people who are worried about children being sexually abused. That can be anyone from parents and teachers to paedophiles who are concerned about their own thoughts and actions.
All callers can stay anonymous.
But if they give a real name, and say anything that makes the call handler think a child or anyone else is at risk, the charity will report it to the authorities.
The foundation also runs face-to-face sessions for people who have viewed images of abuse or committed abuse. Non-offenders can also be treated but the cost is between £700-£1000 and there is no anonymity.
Another charity, StopSO (the Specialist Treatment Organisation for the Prevention of Sexual Offending), can help paedophiles who have not offended by putting them in contact with a specially trained therapist in their area.
But funding - or the lack of it - is an issue. The cost of treatment is an obstacle to taking it up.
StopSO chief executive Juliet Grayson is calling for more government support in the UK. "Surely prevention is worth investing in, saving lives and money."
The National Association for People Abused in Childhood (NAPAC) has a slightly more nuanced view.
It welcomes any work to prevent sexual abuse. But it points out that survivors need support too.
Chief Executive Gabrielle Shaw says: "Support for survivors and victims of abuse is woefully inadequate across the UK.
"This is not an either/or situation, but government and society at large need to realise that more resources are necessary across the piece."
The NSPCC echoes this. It argues that it is "vital" to support both potential offenders and any victims.
The Home Office acknowledges the need for services.
"It is vital that every effort is made to prevent offending in the first place. We are supportive of efforts in this space and would welcome further innovative work by charities and the private sector to better protect children from harm."
In other words, there seems to be a consensus between government, experts and charities that treating paedophiles would help prevent children being sexually abused.
But it's striking that none of the young paedophiles that I've contacted have had any professional help.
They seem to get the most support from other paedophiles.
Adam credits online forums dedicated to non-offending. He says they help reiterate that offending is wrong.
"I've realised that you can actually be happy, and anti-contact and just be who you are."
Jake agrees that these online groups helped him to become firmly "anti-contact". "It made me realise how bad my thinking was starting to get."
He's certain that he will never offend, insisting over and again that if he ever was tempted, his anti-contact online friends would always push him back "on to the right path".
His goal is a relationship with a woman his own age. He says the main barrier is that he "needs to get better at talking to girls".
He kept his paedophilia a complete secret for years, until he had come to terms with it himself.
Then, he was able to tell his friends. He says he felt that he needed to "get it off his chest".
He says the first time he told anyone, it started off almost as a joke. Since then he's told more friends - even accidentally talking about it when he was a "bit too drunk".
But the people he has told have all taken the news "surprisingly well".
He explains: "I mostly kind of say that I'm attracted to people younger than myself, and that I haven't actually hurt anyone and I'm not going to.
"They ask questions and stuff, but I think they believe me."
Adam also told some friends and got a supportive reaction. He says he felt almost high the first time.
Telling his mum was much more complicated though.
He didn't plan it, but one day she found him crying. She asked him what was wrong but he told her he couldn't talk about it.
She thought that maybe he was gay, and asked if it was because he liked men. He said no, so she guessed again.
Did he like women?
And eventually, she asked her son if he liked children?
Adam says she believed that he would never abuse a child. But she couldn't hide her reaction when he told her that he was attracted to children as young as one.
Looking at him tell this story, you realise how slim and slight he is. It reinforces how young he is, even now. Normally he speaks clearly and fluently, but for this, there are long pauses and repetition.
"She... kind of didn't believe me… She, she, she, erm, she was saying 'That's too young'.
"She had to keep asking me if that was right. Her face was kind of just blank, she was looking at me like completely blankly. As if disbelieving kind of thing.
"She just didn't really believe how young it was. It was horrible. It felt horrible because I didn't want to make her feel bad and I didn't want to be a bad son.
"I just felt so... disgusted with myself I guess. She made me feel like that."
When asked about his hopes for a happy and fulfilled future, Adam bleakly says: "I don't know."
He's still so young. I point out that he might be totally convinced now that he will never offend, but that he's got a long life ahead of him.
But he's firm. "I've never been one to hurt people in any way, children, adults, anyone. I just don't think I have it in me to hurt anyone."
Illustrations by Katie Horwich
Watch the BBC's Victoria Derbyshire programme on weekdays between 09:00 and 11:00 on BBC Two and the BBC News Channel.