She sent cell phone video shot by her son of the incident - which she said happened Monday - to the ABC11 newsroom Tuesday.
The video - shot from behind a man's head - shows a laptop computer on a desk in front of him with video of two people having sex playing on the screen.
The student who took the video says it wasn't the first time he'd been shown porn videos in class.
Robert Hester says he told his mom, but she didn't believe him.
"All of my boys told me that they're watching porn at school and I never believed them, because they're supposed to have internet blocks here at the school house," Robert Hester's mother Bobbie Ross said.
So her 13-year-old son decided to use his phone to prove it.
"I said, 'Mom I have a porn video on my phone,'" Hester said. "She said, 'No.' I said, 'My teacher watches porn.'"
The 8th grader says he showed his mother the video footage he took during band class Monday, hoping to prove he wasn't lying.
"That's when I lost it," Ross said. "I called the sheriff and got him to come to my house that night."
A spokesperson with Halifax County Schools said the teacher, Archie McLeod III, is on unpaid suspension while the Halifax County Sheriff's Office conducts an investigation.
McLeod, 51, is reportedly seen on the video.
"He looked like he didn't care," Ross said. "I mean he saw (my son) recording him and he pretty much throws his hand up and turns around and keeps watching. It makes me mad, I mean just to know that I send him to school to learn, to get an education and he's here watching porn with his teacher."
Ross says she wants McLeod to be prosecuted and hopes other parents learn from her mistake of not believing her son at first.
"When your kids come home telling you something like they're watching porn or doing this and that look into it, cause there's no telling what's going on in those schools," Ross said.
Major Bruce Temple with the Halifax County Sheriff's Office says Mcleod is charged with 11 counts of disseminating obscene material to minors under the age of 16 and 11 counts of contributing to the delinquency of a minor --one count for each of the students authorities believe viewed the video.
Detectives said during their investigation, they recovered the computer and the video.
McLeod's bond was set for $40,000. He bonded out of jail Wednesday morning. He is scheduled to appear in court on Feb. 22.
According to a bio on the Davie Middle website, McLeod is from Fayetteville. He got a graduate degree at North Carolina Central University.