'Paedophile tried to silence my teenage son about abuse'

Warning: This story contains descriptions of sexual assault and names have been changed to protect the identity of the victim

"Mummy, Stephen-Lee is going to ask you if he can stay in our house tonight, but will you say no?"

After reading those words in a text message, a mother from Belfast said she knew then that convicted paedophile, Stephen-Lee McIlvenny, 21, was abusing her son.

"That was a big wake up call for me," Michelle (not her real name) told BBC News NI.

"I even started saying it out loud, asking my son: 'Are you both in a relationship? Because if you are I am phoning the police because he is grooming you'," she said.

Ryan, whose name has also been changed to protect his identity, was 14 years old when he first met McIlvenny, who was 18 at the time.

"One weekend when I was away for a night, my eldest daughter caught McIlvenny assaulting my son in his room," said Michelle.

Her son, Ryan, had just turned 15.

Over the next two years, McIlvenny blackmailed, intimidated, raped and beat Ryan so hard he caused a bleed to his brain.

"He beat him so hard and wasn't prepared to stop," said Michelle.

"If people didn't stop to help, my son would have been dead and I think that was Stephen-Lee's intention because the sexual abuse was going to come out.

"I believe he tried to end my son's life."

McIlvenny admitted 77 charges against three teenage boys.

The charges included rape, blackmail, grievous bodily harm and inciting children to engage in sexual activity. He was described in court as a "callous paedophile".

He was handed a jail sentence of 23 years in March.

"What he did to those boys was horrifying," said Michelle.

"He raped my son, he groomed my son, he beat my son, he took my son's virginity. Stephen-Lee McIlvenny is a monster.

"We found messages on his iPad from Stephen-Lee - threats and blackmail - but I couldn't figure out why he was doing it.

"Looking back on it now, I knew. My gut was telling me that it was happening but I was being told it wasn't happening.

"I think I just didn't want to accept that the sexual abuse was happening."

Ryan was 16 years old when he told his mother about the abuse.

"He was so upset, he couldn't say it, he couldn't talk, so he wrote it down," his mother said.

"I still to this day couldn't bring myself to read the full letter."

After the details of the abuse emerged, Michelle phoned the police.

Mobile phones were seized and police found extreme pornography on McIlvenny's devices.

They uncovered more than 200 indecent images and videos either recorded by McIlvenny or that had been sent to him through blackmail and intimidation.

He had uploaded videos of the abuse onto a pornographic website and was being paid to live stream some of the abuse.

Michelle added: "He filmed those kids' abuse. He had those boys terrified, absolutely terrified.

"He was drugging some of the boys, threatening them with dissident groups.

"I have no words for how disgusting McIlvenny is. He is vile."

Police said McIlvenny preyed on children. He used the photographs and videos of the sexual assaults as a way of gaining control over the boys.

"I had always told my daughters to be careful but I never had that conversation with my son," said Michelle.

"There is a shame for wee boys that they feel like they cannot come out and tell people - there is a stigma around sexual abuse in boys."

Michelle said her son has suffered profound physical and emotional trauma as a result of McIlvenny's abuse.

"My son was a lovely, quiet, vulnerable wee boy," she said.

"That is why Stephen-Lee targeted my son. It is just so sad that this has happened to him at such a young age and he's had to learn life so hard.

"This is the hardest thing we have ever gone through.

"What McIlvenny has done to my son is unforgivable. There is no remorse in him.

"I tell my son, 'McIlvenny is in the gutter and you need to rise above and do well in life and sicken him.'

"But my son is an inspiration. He is a great wee boy and is growing into being a great wee man. Nothing will stop him.

"Stephen McIlvenny won't stop him, that's for sure."

If you have been affected by the issues raised in this article, help and support can be found at BBC Action Line.