Charities and educational groups are drawing up their own guidelines for teaching about sex and relationships in school.
It follows the government saying it had no plans to update current guidance, which is nearly 14 years old and doesn't mention the internet.
Campaigners claim advances in technology mean the advice is outdated.
They're concerned many teenagers aren't taught about issues like sexting, consent and healthy relationships.
On Tuesday the House of Lords will discuss a call to make sex and relationship education compulsory at all ages.
Newsbeat spoke to two friends from Luton who went to different schools and had very different experiences of sex education.
They're now volunteering as peer counsellors for the sexual health charity Brook.
Brogan Hardiman, 17
"I didn't really have any.
"We had a science teacher and it was just a bit of science from a book.
"It didn't tell you much about sex - just about sexual organs: 'The penis does this, the vagina does this, blah blah blah and not much more than that'.
"I feel disappointed that the school let us down. They could have done better and taught us more."
Lisa Fontanelle, 18
"In all of my schools it was really good, from primary school right through to college.
"Professionals came in from outside, there were regular sessions and it was in-depth.
"We were comfortable with the teacher and we asked questions. We talked about relationships and how to sustain a relationship.
"There are always going to be some people who don't listen, who look at the teacher and think 'what do you know, you had sex 50 years ago.'
"People did mess about at first but after that we were so open with each other that it became normal.
"We even had someone who came out as bisexual in class."
What happens next?
The Prime Minister said recently that sex education could be improved but added he didn't want a "mega debate" over every part of it.
The Sex Education Forum, the PSHE Association and Brook will soon release new guidelines for teaching the subject.
A Department for Education spokesman said it was better to refer schools to the experts' advice, than rewrite its own.
Labour is trying to get Lords to vote in favour of making sex and relationship education compulsory at all ages, to make sure pupils are taught about consent and respect.
The Department for Education's response to that said: "Sex and relationship education is already compulsory in all maintained secondary schools and primary schools are able to teach it as well.
"Our statutory guidance, which all schools teaching sex and relationship education have to follow, explicitly states children must learn 'how to recognise and avoid exploitation and abuse'.
"Teachers must also cover sexual consent and the importance of stable relationships.
"From the age of five children are taught how to stay safe online and schools are already able to talk about the dangers of pornography in an age-appropriate way."
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