Mary Kay Letourneau's Husband Vili Fualaau Reportedly Feels He 'Lost a Piece of Himself' Following Her Death

Vili Fualaau is mourning the loss of his ex-wife and the mother of his two children, Mary Kay Letourneau. Letourneau passed away on Monday following a months-long battle with cancer. She was 58. Although the couple had a controversial relationship, with Letourneau receiving to jail sentences, Fualaau "lost a piece of himself" when she died.

Speaking with PEOPLE shortly after Letourneau's attorney, David Gerke, confirmed her passing to media outlets, a close friend of Fualaau opened up about the emotional toll her death has had on him. According to the source, although Fualaau "understands how f— up everything was in how they got together," he "can't turn off his feelings completely" and Letourneau's death was "a big loss for him." The source said that Fualaau "would always say that she was his first love."

The former couple's highly publicized relationship began with a kiss in 1996 when Faulaau was a 12-year-old sixth-grade student. That kiss led to a sexual relationship that became public after Letourneau's then-husband found a love note written to Letourneau from Fualaau. Letourneau would go to jail not once, but twice, receiving a light sentence of six months in jail with three of those months suspended after she pleaded guilty to felony second-degree rape of a child and the second sentence of seven years in prison after she was caught having sex with Fualaau in a car. By the time Faulaau was 15, Letourneau had become pregnant with his child twice. They later married and raised their two daughters together.

Although the couple had eventually split and had been separated for three years, Fualaau was at Letourneau's side throughout her battle with cancer. According to PEOPLE's source, the couple "still had love for each other." Letourneau and Faulaau did not speak with one another every day, but Letourneau "would update him on her cancer treatment." The source explained that "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." Towards springtime, however, "the thinking was that she was going to need a miracle."

As Letourneau's health deteriorated, cancer having "spread so much" by July, "she started saying her goodbyes." Letourneau would reportedly "talk to Vili or he would call her to see how she was doing." According to Gerke, who spoke to Today, Faulaau eventually "moved back from California, gave up his life there, and for the last two months of Mary's life he stood by her 24/7 taking care of her."

Letourneau's family has since released a statement, saying that she "fought tirelessly against this terrible disease." At this time, they are asking "for privacy and respect for our desire to focus on the road ahead for all of us who make up Mary's collective family."