A California high school teacher is being investigated by the school board after she revealed she'd got her students to pledge allegiance to the gay pride flag instead of the American one.

Kristin Pitzen, of Newport Mesa School District in Orange County, posted a video to TikTok, where she admitted she'd removed the American flag because it made her 'uncomfortable'.

When one of her English class students pointed out it was missing during the Pledge of Allegiance, she told them to recite the pledge to the only flag she did have hanging in her classroom - the gay pride flag.

The TikTok has since gone viral, sparking a backlash from many parents who were angry she was teaching children to 'disrespect' the American flag.

'How can the words "for liberty and justice for all" bring such hate in people? How can anyone have (an) issue with those words?' one user replied. 

Some even questioned why she lives in America, calling on the school to fire her and parents to homeschool their kids.

While others praised her, even going as far to say they wished she taught their own children. 

In the controversial TikTok, Pitzen reveals that the Pledge of Allegiance is read during third-period announcements.

She said she always tells her class: 'Stand if you feel like it, don't stand if you feel like it. Say the words if you want, don't have to say the words.' 

'So my class decided to stand but not say the words - totally fine,' she said.

'Except for the fact that my room does not have a flag,' Pitzen added.

'It used to be there,' she said in the video as she pivots the camera and points to the wall in the front of the classroom.