The Department of Education says there are no plans to make domestic abuse classes compulsory.
Last week the mother of 21-year-old Hannah Fisher, who was killed by her ex-boyfriend, said awareness lessons should be taken in all classes.
Newsbeat has had access to Abersychan School in Pontypool, where the classes are taught.
PC Juliet Murphy from Gwent Police is delivering the Safer Relationships lesson to a group of students aged 15.
Much of the class involves watching videos showing examples of abusive relationships, highlighting helpline numbers and taking part in scenarios.
PC Murphy says: "You could have other people delivering the lessons but they wouldn't have the same experiences we [as police officers] have had."
These lessons are part of a national programme introduced by the Welsh government over the last five years.
Lessons are all tailor-made for each age group and the issue of abuse and violence in relationships isn't raised until secondary school.
Sian, 15, says she has found them useful.
"I really liked the scenario bit," she says. "I was aware of physical domestic abuse, but I didn't think of the others. I didn't realise how many helplines there were.
"I've never personally experienced it myself as a boy," says fellow pupil Jordan. "But it's good to know there is help out there for men, because they suffer it too."
Last year police say 763 Safer Relationships lessons were delivered across Wales.
The lessons are part of PSHE (Personal, Social and Health Education) but not all schools in the UK teach them and many parents opt out.
But Joe Hayman from the PSHE Association believes the lessons are necessary.
"I'd suggest a victim of domestic abuse may not be in the best position to do their English homework when they get home," she says.
"Eighty-five per cent of parents have consistently told us they want high quality relationships and sex education."
In a statement the Department of Education says they want teachers to have the freedom to tailor their teaching so it meets the needs of their students as they know pupils best, not politicians.
The Welsh government says schools have to offer PSE as a subject but it's up to them and parents if they want to deliver the domestic abuse awareness lessons as part of it.
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