A former Texas teacher has begun a 10-year prison sentence as of this past Friday after she was convicted of having sex and an ongoing relationship with a student.

The unusually long sentence was handed down for Elizabeth Ramsey, an algebra teacher, who’d had sex with a then-17-year-old male. The student had told his mother, Sandy Washington, that it had been going on for roughly two years.

“She was actually writing letters saying he was in tutoring,” his mother said. “They were having sex at school. They were having sex at her house.”

Ms. Washington says she was initially excited when her son, who has Asperger’s Syndrome, started to make friends his sophomore year at Duncanville High School. She then learned that the wayward teacher had taught her son to buy marijuana, make brownies, and give them away.

“He finally had friends and they weren’t true friends. That hurt,” said Washington.

The affair only ended after Ms. Ramsey’s husband came home and nearly caught the two with their pants down. The young victim then “had a psychological breakdown,” according to his mother.

“She discarded him like a piece of trash,” she says.

A charge of sexual assault was dropped in exchange for Elizabeth Ramsey pleading guilty to having an improper relationship with a student. She received 10 years in return.

“They usually end up on probation, but when there are extenuating circumstances like in this particular case, 10 years makes sense,” says attorney Pete Schulte, who reviewed the case for a CBS affiliate.