(CNN) Every year Oklahomans for Equality takes a group of LGBT students to the state Capitol in Oklahoma City to learn about advocacy and government.

But this year's field trip came with a painful and unexpected lesson.

As the students arrived Monday they learned that a Capitol staffer had sent an email that day throughout the state offices warning, "there are cross-dressers in the building."

As reported by the Tulsa World , the email also said that "per the Speaker's office," House and Senate pages were being allowed access to private bathrooms -- presumably to avoid the visiting gay, lesbian and transgender students.

So Toby Jenkins, director of Oklahomans for Equality, led the students to the office of House Speaker Charles McCall to complain.

And they posted the whole thing to Facebook Live.

"Someone owes all of these children an apology," Jenkins told staffers who greeted them at McCall's office. "They feel like they have been insulted."

In the video, Jenkins explained that "cross-dressers" is an offensive term and that the state's policy-makers, who influence Oklahoma students' education, should not use it.

McCall's staff told Jenkins that the House Speaker was not available to meet with them.

But McCall later issued a statement disavowing the email.

"The email was not authorized by me, my staff or my office. It was sent unilaterally by a House staff member without any input or permission. I was unaware that such an email was being sent, and the remarks contained in the email are not condoned by me or the Office of the Speaker," he said. "All Oklahomans should feel welcome in the Oklahoma Capitol building. We are looking into this matter, and it will be taken seriously."

The email and the students' Capitol visit became national news and drew criticism on Twitter about "Oklahomaphobia."

Oklahomophobe, where the wind goes whistling through the braaaiin...: https://t.co/DWou4OfYNH via @thedailybeast — Carol Kaufman (@peri_gisele) April 12, 2017

"Several of the students were embarrassed and hurt," Jenkins said in a statement issued later. "They faced the hate in the hallways of the Capitol just like they do every day in the hallways of their high schools."

But he and the students appeared undeterred.

"If the Oklahoma Capitol was afraid of us being there, we are sending you an FYI: we will be back next year," he said.