Nation A substitute teacher sang Britney Spears’ ‘Toxic’ on a karaoke machine. He was asked to leave early. December 7, 2021December 7, 2021 Asha C. Gilbert, USA TODAY Comments Off on A substitute teacher sang Britney Spears’ ‘Toxic’ on a karaoke machine. He was asked to leave early. A substitute teacher in Austin, Texas was asked to leave after singing Britney Spears' 'Toxic' on a karaoke machine he brought to the classroom.