Even the most drama-free relationships take work — and Mary Kay Letourneau and Vili Fualaau's marriage is anything but drama-free. Having started their illicit affair when Fualaau was just 13 and Letourneau was 34, the spouses of 10 years have had to overcome almost impossible odds to be together. And while they're still happily wed with two kids, they've had more than their share of highs and lows. 
 
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 "I don't think there's ever a full 10 good years of marriage. You have your ups and downs in marriage," Fualaau, now 31, told Barbara Walters in an exclusive interview set to air Friday, April 10, in honor of the couple's upcoming 10th wedding anniversary. "But, you know, what matters is how you pull through all the bad times." 
 
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 Those bad times include a seven-year prison sentence for Letourneau, now 53, who was a married mother of four when she and Fualaau — then a student in her sixth-grade class — began their sexual relationship. By the time he was 15, they had two kids together, Audrey and Georgia. 
 
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 "It was a huge change in my life, for sure," Fualaau told Walters. "I don't feel like I had the right support or the right help behind me…From my family — from anyone in general. I mean, my friends couldn't help me because they had no idea what, what it was like to be a parent, I mean, because we were all 14, 15." 
 
 As was well-documented at the time, Letourneau and her student-turned-lover wed in 2005, a year after she was released from prison. In the time since, they've kept a relatively low profile — but that's about to change. 
 
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 "It is our 10-year anniversary, and we already know that no matter how protective we are, that there's going to be a wave of intrusion in our life right now that we can't stop," Letourneau explained to Walters. "So it's about doing the most responsible thing to protect our girls for the inevitable." 
 
 Barbara Walters' interview with Mary Kay Letourneau and Vili Fualaau airs Friday, April 10, on ABC's 20/20. 
 
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 Friday, April 10, 10 pm ET on ABC 
 
 In an exclusive interview with Barbara Walters, Mary Kay Letourneau Fualaau and Vili Fualaau sit down together on the eve of their 10th wedding anniversary, sharing intimate details about their headline-making marriage. Mary Kay Letourneau Fualaau is the former Seattle-area sixth-grade teacher who, at the age of 34, had an affair with her 13-year-old student, Vili Fualaau, and served seven and a half years for their inappropriate relationship. In the candid interview, Mary Kay tells Walters what makes their marriage work in spite of their huge difference in their age. She also discusses her surprising plans to teach again, as well as her intentions to have her status as a registered sex offender lifted. Vili Fualaau, meanwhile, discusses his bouts with alcoholism, depression and why he believes the system failed him while he was still a minor. 
 
 Also, for the first time ever, viewers will meet their two teenage daughters, Audrey and Georgia, who are now older than Vili was when he conceived them. The interview airs on “20/20” on FRIDAY, APRIL 10, 2015 (10:00 – 11:00 pm ET) on the ABC TELEVISION NETWORK. 
 
 Letourneau first spoke to Walters in 2004 after being released from prison. At that time, she said that she wanted to marry her former student, who was 13 when their liaison began. “We’ve always planned that and it hasn’t changed,” she told Walters. ||||| Former schoolteacher Mary Kay Letourneau and husband Vili Fualaau, with whom she began a sexual relationship when he was her sixth-grade student in Seattle in 1996, have legally separated and a reconciliation seems unlikely, PEOPLE confirms. 
 
 “They’ve been having issues for a while now,” says a source close to the couple. “They tried to work through them, but it didn’t work. They’re still committed to being good parents to their children.” 
 
 There is no third party involved in the relationship, the source says. 
 
 Letourneau’s friend and former attorney David Gehrke says it was Fualaau who filed for separation. 
 
 “She could try to contest it, but that’s legally tough to do,” he says. “Perhaps if they want to figure out about the children and child support, but their kids are getting pretty old now.” 
 
 “When one person is unhappy in the relationship, the other person can’t be happy either,” he continues. “And there are two people in this relationship.” 
 
 Their initial affair — which began while Letourneau was a 34-year-old mother of four and Fualaau was 12 — ignited national controversy and revulsion, particularly after she defied a court order to stay away from Fualaau. “The two of them want to be together,” a friend of Letourneau’s told PEOPLE in a 1998 cover story. “They’re drawn together like magnets.” 
 
 Prosecutors took a different view, arguing at the time that Letourneau “doesn’t believe she did anything wrong.” 
 
 After the relationship was revealed, she pleaded guilty to two counts of second-degree child rape and was sentenced to seven and a half years in prison. 
 
 She and Fualaau married in May 2005 after she was released, and they have two children. 
 
 “I’m convinced they were totally in love,” Gehrke says. 
 
 Mary Kay Letourneau in 1996 AP Photo/Seattle Post-Intelligencer 
 
 Mary Kay Letourneau in court in Seattle in February 1998 Alan Berner/AP 
 
 A March 1998 PEOPLE cover story on the Mary Kay Letourneau case 
 
 The couple’s second child, Georgia, was born while Letourneau was behind bars. 
 
 They sat down with PEOPLE for an extensive interview in 2006. Fualaau, then 22, said he sometimes wondered about the past. 
 
 “I think, What would my life have been like if I had never made a move on Mary?” he said. “What if I had kept it as a crush and left it at that? Where would I be and where would she be — what would life be like?” 
 
 But he said he didn’t see an answer to such speculation. “I can never see more than the question.” 
 
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 Vili Fualaau in October 1998 John Froschauer/AP 
 
 Vili Fualaau and Mary Kay Letourneau (center left and center right) with their two daughters, Audrey (far left) and Georgia (far right), in 2015 Heidi Gutman/ABC/Getty 
 
 Nearly a decade later, in 2015, Fualaau and Letourneau sat down for an interview with ABC’s Barbara Walters, where they discussed their relationship, marriage and parenting. 
 
 Letourneau revealed then that she would like to get her name taken off the sex offender registry, though officials in Washington state tell PEOPLE she is still a registered offender. 
 
 “There is a story of us that has a life of its own, but it’s not our story,” she told Walters. 
 
 When Walters asked Fualaau how he’d feel if the girls came home and said they were sleeping with their teacher, he responded, “I don’t support younger kids being married or having a relationship with someone older. I don’t support it.” 
 
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– The mother of all teacher-student sex scandals is returning to the national spotlight—just ahead of the 10th wedding anniversary of the two people involved. That would be Mary Kay Letourneau and husband Vili Fualaau, whose interview with Barbara Walters airs on ABC tomorrow night. Letourneau is 53 and Fualaau 31, but their relationship made national headlines when Letourneau became pregnant with Fualaau's child when he was all of 13. She had been his sixth-grade teacher. Letourneau spent nearly eight years in jail, but the couple stayed together and now have two teenage daughters, Audrey and Georgia. ABC is providing a few teasers, including the nugget that Letourneau wants to teach again, presumably only after getting her status as a sex offender lifted. Fualaau, meanwhile, will discuss his struggles with alcoholism and depression, notes Us Weekly. "It was a huge change in my life, for sure," Fualaau recalls of the scandal. "I don't feel like I had the right support or the right help behind me ... from my family, from anyone in general. I mean, my friends couldn't help me because they had no idea what, what it was like to be a parent, I mean, because we were all 14, 15." Letourneau says they did the interview in part because they figured they'd be deluged with attention ahead of their May 20 anniversary, like it or not. "So it's about doing the most responsible thing to protect our girls for the inevitable."