The bus driver convicted of leaving a 19-year-old autistic student on a hot school bus two years ago was having sex with another driver while the teen died, according to legal documents filed Tuesday by the attorneys of the teen’s family.

The documents included a Whittier police report showing officers recovered more than a dozen sexually explicit text messages sent between Armando Ramirez and his female co-worker the morning of Hun Joon “Paul” Lee’s death.

In interviews with Whittier police, the two drivers said they met at Ramirez’s house to have sex that day. The female driver told police she felt guilty that while she and Ramirez were having sex, “this kid was dying, and we were laughing.”

Ramirez was sentenced in January to two years in prison after pleading guilty to one count of dependent adult abuse in connection with Lee’s death.

Lee’s family is now suing the Pupil Transportation Cooperative, the bus company that employed the two drivers, as well as the Whittier Union High School District.

Robert Glassman of Panish, Shea & Boyle LLP is an attorney for the family. He said the text messages showed Ramirez was preoccupied with going to have sex with his girlfriend while he was supposed to be doing a sweep of the bus.

“He neglected the safety of students, of Paul that day, so he could have sex with the other driver,” Glassman said.

Glassman alleged that the school bus company was permissive in its treatment of relationships between employees and what its workers did on their breaks.

The bus company, PTC, whose lawyers did not return phone calls Tuesday, said in court documents there were no merit to the claim.

Depositions filed as evidence in the lawsuit Tuesday showed the female driver interviewed by police said PTC knew of the affair and did nothing to stop it.

Ramirez left the PTC parking lot without permission to see his girlfriend and did not return to his midday or evening shifts, Glassman said.

He added that PTC has not reformed its policy on employee fraternization.

The filing was in response to PTC’s motion of summary adjudication earlier this year to a portion of the Lee family’s lawsuit. The family’s lawyer amended their original complaint to include a third action of neglect by PTC, which would have put the company in violation of the Elder Abuse and Dependent Adult Civil Protection Act.

Under this statute, PTC could be liable for attorneys’ fees and other damages not usually allowed in a wrongful death case.

Lee, who was a student at Sierra Vista Adult School, was left on a bus for hours on Sept. 11, 2015.

Lee’s family, father Sang Sik Lee and mother Eun Ha Lee, became worried when the teen didn’t come home and called the school and Whittier police.

The young man was found unconscious and lying on the floor of a school bus parked at Mulberry Drive and Greenleaf Avenue in Whittier. Lee died at the scene.

The monetary amount will be discussed as part of the trial, which will begin next month, he said.

“The jury, the community will ultimately decide the value of the loss of the relationship between Paul and his parents,” Glassman said.