At least two McKinney middle school students were sent home Wednesday, and several others were told to cover up their "Gay O.K." message they wore emblazoned on their T-shirts.

The shirts were worn as silent support for a Faubion Middle School seventh grader who recently came out and, as a result, was bullied by other schoolmates.

"Being gay is OK. And it is OK to be open about it," said classmate Anna Thompson, who was one of at least 15 Faubion Middle School students who wore the "Gay O.K." shirts to school.

Thompson told NBC 5 she was approached by an administrator about the shirt almost as soon as she walked in the door Wednesday morning.

"[He] came up to me and said that he doesn't believe this message is school appropriate," Thompson said.

Other students said they did not encounter any resistance to the shirt until lunch time.

"We were doing perfectly fine until lunch," said Sammy Heiman, a seventh grader who designed the shirts. "And then [the administration] called us all out, all the people wearing them, called us out of the cafeteria. And people started getting rowdy because they knew what was going on. They were making us take off the shirts."

Videos posted to Twitter on Wednesday showed a cafeteria full of students chanting, "Gay O.K." after some students had been removed from the room.

A separate video shows a student, who was not wearing one of the controversial shirts, arguing with an administrator before he is seen slapping a cellphone from the hand of the man, while several students are heard shouting and encouraging the student.

"In this particular case, a verbal disruption occurred between a large number of students in the cafeteria as a result of the shirts," said Cody Cunningham, spokesman for the McKinney Independent School District. "This was not a civil debate, but rather yelling and shouting, and [it] alarmed a large number of students."

"While we respect student free speech, our primary obligation is to ensure a safe and productive learning environment for students in McKinney ISD," Cunningham added.

The students told NBC 5 they did not expect to be penalized for wearing the custom-made shirts Wednesday because the wording of the district dress code specifically forbids, "Clothing including tee shirts which displays sex, violence, drugs, tobacco, alcohol, death, gang or hate slogans or pictures."

The school district's concern, however, was not the specific message on the shirts, according to Cunningham. Administrators instead focused on the portion of the dress code that states, "Any disruptive or distractive mode of clothing or appearance that adversely impacts the educational process is not permitted."

Kristy Heiman, the mother of Sammy and a teacher at a different McKinney ISD school, told NBC 5 she believes the district's statement that it was not the message on the students' shirts that was the cause for concern, but was instead the issue of disruption.

Still, Kristy Heiman said she supports her daughter and her friends.

"I'm just so proud of them. I just want everybody to know that it just takes one person," she said. "This was just supposed to be a nice, quiet five or six kids wearing something. And it turned into something much bigger."