Mrs Izzy Montague, a devout Christian woman, has sued her son's school, Heavers Farm Primary School in South Norwood, London, for requiring him to march in an LGBT pride parade.
The 28-year-old lady testified before the Central London County Court that her child had been made to engage in the "most heinous of the deadly sins" by the school.
According to Metro, on June 19, 2018, the school wrote to parents encouraging them to send their kids to a Pride march.
"Celebrate the differences that make them and their family special," was the advice given to students.
But Montague objected to the Pride celebration and said that her four-year-old son would not be participating.
She got in touch with the school and expressed her disapproval of his participation in the LGBT celebration, claiming it would be "a public display of devotion to values she did not embrace."
Susan Papas, the headteacher, turned down her request, so the woman sent a long email in response.
The headteacher's daughter was wearing a T-shirt that read, "Why to be racist, sexist, homophobic, or transphobic when you could simply be quiet?" when Montague met with Ms Papas on September 19, the court heard.
Judge Christopher Lethem described the woman and her husband as “devout born-again Christians, and they bear a belief that sexual relations should be abstained from or take place within a life-long marriage between a man and a woman and any activity outside those confines is sinful.”
“They also say pride is considered to be the most serious of the deadly sins,” Lethem added.
It was the first time that a UK court will scrutinise the legality of teaching about LGBT issues in primary schools.
While the school has defended the parade and said it was “a celebration of what makes the children proud”, the woman disagreed.
“It felt like it was lecturing me about something to do with British values and somehow we weren’t adhering to British values,” Montague said.