A Utah substitute teacher has been fired after allegedly launching into an anti-gay rant before a classroom of fifth graders.

The incident happened last week when the teacher, who was subbing at Deerfield Elementary School in Cedar Hills, Utah, asked the students what they were thankful for.

One of the students, who was adopted by professional choreographer Louis van Amstel and his husband, said he was thankful for his two fathers.

The teacher then allegedly went into a 10-minute tirade about how “homosexuality is wrong.”

The school confirmed the incident to ABC News.

Van Amstel posted a report of the alleged incident on his social media account:

Kelly Services, which provides substitute teachers for the school district, confirmed the teacher’s dismissal to ABC News.

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

Van Amstel has appeared multiple times on ABC's “Dancing with the Stars.”