Parents' right to remove children from sex and relationships education could be scrapped under reform plans.
The idea is being considered by the Welsh Government as part of its curriculum changes.
New Relationships and Sexuality Education (RSE) is being introduced in primary and secondary schools.
Education Minister Kirsty Williams said she was considering whether allowing parents to remove pupils from the lessons was "still appropriate".
The consultation paper said arrangements had been unchanged for decades and it was "keen to explore potential approaches to modernise".
Ms Williams told Wales Live: "We don't give parents the right to withdraw from specific parts of the curriculum - maths or maybe science if somebody is concerned they don't believe the science around climate change - we don't give parents the right to withdraw children from those lessons.
"So it's about checking in to see if these rights are still appropriate as we move forward with our curriculum reform.
"We will do this sensitively and we will be listening to views and we're not charging ahead in a gung-ho fashion because we realise these are complex but highly important issues and that's why we're listening seriously to people's views."
Currently, Sex and Relationships Education must be taught in secondary schools, but is optional in primary schools - under the new curriculum RSE will also be taught in primary schools.
Government guidance said it should be "developmentally appropriate" and recognise the importance of "diversity and difference across a range of identities related to relationships, sex, gender, sexuality".
There have been protests by parents at a school in Birmingham as they feel classes about LGBT rights were age-inappropriate and incompatible with Islam.
Under the new curriculum, schools would be legally obliged to teach RSE, but the guidance on which areas schools should focus on would be advisory.
However, the Welsh Government said it "fully expects schools to be teaching RSE that is inclusive of LGBTQI+ learners".
Some religious groups, including the Christian Institute, Muslim Council of Wales and the Catholic Education Service, are opposed to the right of withdrawal being removed.
The National Association of Head Teachers said the decision "must continue to sit with parents and carers" although key elements relating to safeguarding must continue for all children.
But the Church in Wales, National Secular Society and Children's Commissioner have backed the idea.
The Church in Wales said RSE helped young people "develop an understanding of tolerance and diversity" making it "fundamental to the core purposes of the new curriculum".
The consultation closed on Monday and the government will analyse responses before making a decision.
- BBC Wales Live - BBC One Wales, 22:30 GMT, 27 March