Washington – from www.abcnews.go.com – In a small town like Prosser, Wash., everyone knows everyone else. And these days, everyone definitely knows the Lusks.

Linda Lusk is the former mayor of the town — she became Prosser’s first woman mayor in 2003 — and Kevin Lusk is the principal of Prosser High School. Former high school sweethearts, the Lusks drifted apart after graduation, married other people and had children.

But 15 years later, after each divorced their first spouses, they re-connected.

“It was like no time had passed,” Linda Lusk remembered. “Everything just sort of picked right back up again where it was. There was that spark there.”

The Lusks married and had two more children. Their house, a block away from the high school, was a popular hangout spot for the Lusk children and their teenage friends.

The home was “a safe place where parents, you know, didn’t mind their children going to,” said Heidi Frank, the mother of a Prosser High School football player. “They were people in the community that were trustworthy.”

Frank doesn’t feel that way anymore.

In April, 2010, the small town was suddenly rocked by a rumor that Frank’s son Bubba, then 14, engaged in an inappropriate relationship with Linda Lusk — a relationship that the teenager alleges culminated in oral sex.

Bubba didn’t deny the rumors. In fact, the teen bragged about it to his friends.

Lusk, he would later tell “20/20,” didn’t take advantage of him.

“I basically knew what I was doing,” he said.

His mother, Heidi Frank, saw it differently.

“In my eyes, I still, as a mother, see a vulnerable 14-year-old child,” she said.

Linda Lusk, now 51, concedes that her relationship with Bubba crossed a line — but the alleged oral sex, she maintained, never happened.

Lusk and her husband said that to understand why she became entangled with Bubba at all, it’s important to understand her relationship with another boy — her son, Taylor, who died in 2009.

Taylor suffered from the rare genetic disorder Trisomy 13. When he was born, doctors told Lusk he was “incompatible with life” and wouldn’t live past a week.

But Taylor defied the odds under his mother’s constant care and, by 2009, had turned 15.

Lusk did everything for Taylor. She fed, changed and moved him. Countless times, she had to literally restart his heart with rescue breathing.

On a spring afternoon two years ago, Lusk left Taylor at home with her other kids, as she often did, to work a while at her handbag shop. By the time she got back, Taylor’s breathing had stopped one more time, and this time would be the last.

“When I got home, he was just gone,” Lusk said. “I just found him in bed, not breathing. And in retrospect, I suppose I blame myself a little bit — that I wasn’t there and I could have stopped it.”

Lusk’s family said she changed after Taylor’s death. She was steeped, she said, in depression and guilt. And while Lusk was anxious to care for others, in those weeks and months after Taylor’s death, she did nothing for herself. She never sought professional help.

“My whole way of life was gone,” Linda Lusk said. “I would get up in the morning and go into [Taylor’s] room, just automatically, and just go, ‘Oh, he’s not there.'”

With Taylor gone, Lusk focused her attention, she said, on another boy in need: Bubba Frank.

A friend and one-time boyfriend of Lusk’s daughter, Karlie, Bubba frequently visited the Lusk home. Lusk had a soft spot for Bubba: The teen, she said, was troubled by his parents’ divorce and clearly needed nurturing.

“She just tried to comfort me, for the most part,” Bubba told “20/20.”