Vili Fualaau “lost a piece of himself” when Mary Kay Letourneau — his former sixth-grade teacher whom he later married — died of cancer this week.
Letourneau and Fualaau began an illegal relationship when he was her 12-year-old student, and she was ultimately sentenced to more than seven years in prison for child rape. Letourneau remained a registered sex offender in Washington state after getting out of prison, and the pair married in 2005 before Fualaau filed for legal separation in 2017.
You’ll get the latest updates on this topic in your browser notifications.
A close friend of Fualaau’s tells PEOPLE that although they had been broken up for three years, Letourneau kept him in the loop on her health and the former couple “still had love for each other.”
“They didn’t speak every day, but she would update him on her cancer treatment,” the friend says. “At the beginning, the talk was that she was going to beat it, that even though the prognosis wasn’t good, that she’d fight with everything she had, and that she had a shot of surviving it.”
The friend explains that “as things got into the springtime, the thinking was that she was going to need a miracle.”
Vili Fualaau, Mary Kay Letourneau and daughters
RELATED: Mary Kay Letourneau’s Family Mourns Loss After ‘Arduous’ Cancer Battle: ‘We Are Deeply Saddened’
By June, Letourneau’s cancer had “spread so much” that “she started saying her goodbyes,” according to Fualaau’s friend.
“She would talk to Vili or he would call her to see how she was doing. The marriage had split up, but they still had love for each other. They had children together and he would always say that she was his first love. So of course he is sad at the loss. He’s sad for the girls, but he’s also sad for himself.”
Letourneau became pregnant twice before Fualaau turned 15, despite court orders aimed at keeping them apart, and the two share daughters Georgia and Audrey.
RELATED VIDEO: Mary Kay Letourneau and Vili Fualaau Spotted Out After Separation: ‘It’s Like They’re Still Together’
“He lost a piece of himself,” Fualaau’s friend adds of her passing. “He understands how f— up everything was in how they got together. He’s not stupid. But he can’t turn off his feelings completely, and it’s a big loss for him. He talked to her right before she passed, and they said everything they needed to say.”
The families of both Fualaau and Letourneau previously said in a statement they are “deeply saddened” by the former teacher’s death.
Vili Fualaau, Mary Kay Letourneau
“Mary fought tirelessly against this terrible disease,” said the family of her cancer diagnosis in the statement, which was provided to writer Danielle Bacher. “Mary, and all of us, found great strength in having our immediate and extended family members together to join her in this arduous struggle. We did our very best to care for Mary and one another as we kept her close and stayed close together.”
Want to keep up with the latest crime coverage? Sign up for PEOPLE’s free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.
Mary Kay Letourneau, Vili Fualaau and daughters
Heidi Gutman/ABC
RELATED: Mary Kay Letourneau Dies of Cancer at the Age of 58
“We are endlessly grateful for the care and kindness received from the amazing professionals involved in Mary’s care,” the statement continued. “Likewise, the kindness and compassion of friends and others who learned of her condition along the way proved an uplifting gift to us all.”
“It is in that spirit that we ask for privacy and respect for our desire to focus on the road ahead for all of us who make up Mary’s collective family,” the families said. “We ask that our boundaries and need for privacy be honored with continued kindness and understanding.”
The families concluded that they intend to “celebrate and honor the wishes of our wife, mother, daughter, grandmother, sister, beloved family member and loyal friend and concentrate on caring for one another.”