Mary Kay Letourneau was a married mother-of-four when she began a sexual relationship with Vili Fualaau, a sixth grade student. She was 34. He was only 12.
In 1997, their illicit affair led to her being sentenced to seven and a half years in jail for second-degree rape of a child, a crime for which Letourneau believes she was wrongfully imprisoned for.
Mary said it was true love, but many others were sceptical. And even so, their relationship endured, with the pair going on to have two children together.
And now, in an explosive investigation, Sunday Night's Matt Doran has looked at the bizarre case in full detail, unveiling that the family are still dealing with the truth of what happened all those years ago.
Keep scrolling as we take a look back at the case that shocked the world.
In 1996, the Seattle-based school teacher, who was 34 at the time, began a sexual relationship with her then-sixth-grade student, Vili.
After being caught, she pleaded guilty to two counts of felony second-degree rape of a child in 1997.
At the time Mary was married to her first husband Steve Letourneau and together they had four kids.
Mary's plea got her a six month sentence, with three months suspended and no contact with Vili for life.
Just one month after her release, Mary was caught with her former student once again, leading to seven years in prison.
When Mary was imprisoned, she was required to have no contact with her former-student but managed to thwart the system using a number of bizarre methods.
According to the Mary Kay Letourneau episode of Barbara Walters Presents American Scandals, the teacher-turned-sex-offender even resorted to smuggling messages in bottles of breast milk.
"Mary stayed in touch with Vili in a lot of different ways," author Gregg Olsen, who has covered the case, told Walters. "One way was to send out messages in the milk bottles that she was — [producing] milk in prison for her babies, so she put little notes in the caps and they went out."
"She sent audiotapes out," he added. "She had prisoners make phone calls for her, because she could not contact him [Fualaau] directly."
The teacher was released in 2004, and the courts revoked the no-contact order.
WATCH: Mary Kay Letourneau and Vili Fualaau separate, but it's not what you think. Post continues...
In 2005, Letourneau and Fualaau were married in front of 250 guests.
They had two daughters Audrey, who was born while her mum was out on bail in 1997, and Georgia, who was born in 1998 while Mary was in prison.
When Mary and Vili chatted to Barbara Walters about their controversial relationship in 2015, they admitted it had been marred by all the media attention.
"I don't know if enough time will ever pass where it will take away what the media did to our story," she mused.
"Because it was so big, and they ran with it so fast. There's a story of us that has a life of its own, but it's not our story."
However, Fualaau filed for legal separation in 2017 after 12 years of marriage.
Fualaau explained he filed for divorce due to a new business venture -- he's hoping to become a distributor for Cigaweed marijuana cigarettes, which requires a license.
"It's not necessarily what you think," he told Radar Online. "Everything is fine between us."
"All the rumours that you hear between us. It's fine," he said. "Of course [we are still in love]. A piece of paper doesn't break someone's feelings!"
"If I decide to be a part of it I have to be licensed and I have to be vetted and so does a spouse. She has a past. She has a history."