Louis van Amstel is speaking out about how his son was bullied by a substitute teacher for having two dads.  (Photo by Alberto E. Rodriguez/Getty Images)
CNN  — 

Former “Dancing with the Stars” pro Louis van Amstel is speaking out after a teacher berated his son for saying he’s thankful for his two dads.

Amstel and his husband, Joshua Lancaster, are in the process of adopting an 11-year-old boy, who is currently in fifth grade. During a pre-Thanksgiving lesson, a substitute teacher at the boy’s Utah elementary school asked his class to share what they were thankful for. According to van Amstel, when the boy said that he was thankful he was “finally going to be adopted by my two dads,” the unidentified teacher responded that two dads were “nothing to be thankful for.” The teacher reportedly went on to lecture the fifth-graders about how she believed being gay is wrong.

Van Amstel, who competed as a professional choreographer on “Dancing With the Stars” for 10 seasons, took to Twitter to say, “our child was bullied.”

“Three female students asked the teacher to stop multiple times, and when she didn’t, they walked to the principal’s office to report her. She was ultimately escorted from the building and, as this unfolded, she continued to argue her point,” he wrote.

He continued: “She also tried to blame our son and told him that it was his fault that she went off. It’s absolutely ridiculous and horrible what she did. We were livid. It’s 2019 and this is a public school.”

“I’m truly disgusted that the bully in this situation is a teacher in a public school.#equalrights #allfamilies #allfamiliesmatter,” he added.

Van Amstel said he and his husband found out about the incident when school administrators contacted him. Van Amstel credited the school for how they handled the incident.

The 11-year-old joined the family after being in foster care for years and experiencing two failed adoptions. Van Amstel said he was “so fearful that this could make us think that we don’t want to adopt him.”

The substitute teacher, who was subcontracted by the Utah school district through Kelly Services, was fired.

“We are concerned about any reports of inappropriate conduct and take these matters very seriously,” a representative for the company said in a statement. “We conducted an investigation and made the decision to end the employee’s relationship with Kelly Services.”

CNN’s Artemis Moshtaghian contributed to this story.