A married South African lesbian couple have been told they should split up and abandon their “lifestyle”, or face the expulsion of their son from his Christian school.

Kally, 26, and Samantha Mabe, 27, were married in 2012, and highly publicised their wedding through magazines and online videos as part of their anti-discrimination activism. The couple said they wanted to show how happy and normal the lives of gay people could be.

They enrolled their son in the Secunda Highveld Christian School in Mpumalanga, and said they were open about their marriage with staff.

“We told the principal and our son’s class teacher… We never hid the fact that he has two mothers, and I filled in my details under the section in the form that asks for the mother’s details and Sam filled in the area that said ‘Father/Guardian’, but also filled in her title as ‘Mrs’,” Kally Mabe told The Star.

“After we told them we were a lesbian couple, the principal said they were Christian and not in a position to judge us.”

However, the couple reports that after their son told his teacher he had two mothers they were called in to meet the principal, who denied she had been told that the two women were married.

Kally Mabe said: “The principal said she could not remember us telling her we were married, and that because they couldn’t differentiate between black names, they were under the impression that I was married to a man.

At a subsequent meeting the couple were told by the school pastor that they would never have been allowed to enrol their son if it had been known they were a lesbian couple.

“He said I could either walk away from my lifestyle and have [my son] stay at the school, or I should take the child out of the school, because he was worried that other children would make fun of him or isolate him,” Kally said, and added that the pastor had threatened legal action if the couple did not cooperate.

Samantha Mabe said: “We enrolled our son in a Christian school because they are supposed to teach love, acceptance and forgiveness as God taught us too. Yet the school stands and teaches hypocrisy and teaches that only some people deserve to be treated in a Christian way and others don’t.”

The Mabes say they will stage a legal battle for themselves and other gay couples if the school keeps up its demands.

Secunda Highveld Christian School declined to speak to press.

A spokesperson for the Mpumalanga Department of Education said: “We view such matters in a very serious light, and even though the school is independent, we will still find out what happened and make sure that whoever worked outside the legal framework is brought to book.”

Although South Africa’s laws are progressive in terms of LGBT rights and gay couples have the legal right to marry, homophobia is still a problem within society.

Last month it emerged that a teenage boy in South Afica died from severe and substantial injuries sustained while attending a camp which has been linked to “gay conversion”, after allegedly being beaten, starved, and forced to eat his own faeces.

April also marked the two-year anniversary of the death of Noxolo Nogwaza, a young lesbian in South Africa, who was raped and murdered after a night out with friends.