"I'm glad it's going to be over," said the mother of the victim, whose identity is protected by a publication ban. "My son doesn't have to talk about it anymore until he's ready to."
MacKean, 64, was also found guilty of communicating for the purpose of obtaining sexual services from a person under 18. He will be sentenced June 24.
The mother said it was painful for her son struggle through police interviews and testify in court, recounting the horror of being chained and sexually assaulted in a ramshackle cabin after he was kidnapped in Halifax.
"He's done a very good job and he's been very strong," she said. "He's just a very brave boy."
The verdict came after more than four hours of deliberations. The trial, which began Monday, heard MacKean and the victim each give their accounts of what happened on Sept. 20, 2012.
The teen testified that he was blindfolded with a sleeping mask and his hands and feet were chained to a bed when a man sexually assaulted him at a cabin about a 90-minute drive southwest of Halifax, where he was kept captive for eight days.
The youth, who was 16 at the time, later told the province's Supreme Court in Bridgewater that a man performed oral sex on him as he cried, unable to move.
The teen, now 17, said he was certain the man was not one of two other men accused in the case, one of whom was later convicted of kidnapping him, because he was able to determine from a limited view beneath his blindfold that the perpetrator was a balding, heavy-set man who wore glasses.
Crown prosecutor Lloyd Tancock said he believes a video of an interview MacKean gave to police after his arrest, during which MacKean said he was inside the cabin and involved in a sexual encounter with the boy, was a major factor in the jury's decision.
Tancock said the case has been an ordeal for the victim and his family.
"It's been a terrible case for the family and it doesn't end here for them I'm sure," he said.
He said he is not yet sure what sentence he will seek.
Defence lawyer Mike Taylor agreed that MacKean's interview with police harmed his client's case.
"It certainly posed problems for the defence," Taylor said. "There were acknowledgments by Mr. MacKean that he had done certain things."
MacKean testified Thursday, saying the youth did not seem upset and was not in chains at the time of the incident.
MacKean denied he performed oral sex on the youth, said he was led to believe the teen was a young adult and that if he felt the youth was distressed, he would have made sure he was freed.
He said he was invited to the cabin by Wayne Alan Cunningham, with whom he had a sexual relationship after the two met at Alcoholics Anonymous meetings.
MacKean said Cunningham suggested in the summer of 2012 having a third person involved during their sexual massages that cost MacKean $45 each. Cunningham told him that person was in his 20s, MacKean told the jury.
MacKean said he believed that based on a photo of the youth he was shown and that in fact, the boy looked to be around the same age as Cunningham, who was 31.
When he arrived at the cabin, MacKean saw the youth blindfolded on a bed, court heard. Cunningham said the youth preferred to have a blindfold on because he was shy, MacKean told the jury.
MacKean said the youth didn't talk while the three engaged in a sexual encounter.
David James LeBlanc, another man accused in the case, was sentenced last June to 11 years in prison after pleading guilty to kidnapping, forcible confinement, sexual assault, uttering threats and breach of conditions.
An agreed statement of facts in LeBlanc's case said he offered the teen a painting job and drove him in a van from Halifax to a cabin in Lunenburg County about 130 kilometres away in September 2012 on the pretext of picking up painting supplies.
The youth later escaped and a woman reported seeing a barefoot teenager at her doorstep, chained at his wrists and ankles.
LeBlanc was arrested in northern Ontario in September 2012. Police were also searching at the time for Cunningham, whose body was later found near the area where LeBlanc was arrested. Foul play was not suspected in his death.