Twenty years ago, a teenage girl describing how 14-year-olds get drunk at discos, and how they "do a lot of stuff - like getting down on their knees and having sex in front of everyone" would have had scandalised viewers protesting about the depravity on television.

However, on the recent Late Late Show that dealt with teenage sex, the audience were neither shocked nor surprised by such a lurid description from a young woman. The identities of other participants who made similar revelations were concealed. This protection helped them to speak openly about their beliefs and sexual behaviour.

The girl who said "you learn from your friends" confirmed what we know from studies. A young man claimed that condoms are the most popular and in his opinion the cheapest and the most effective protection.

I suspect that he was well informed about one aspect of "safe sex": he knew how to avoid being a party to an unwanted pregnancy. He sounded so confident, yet ignored the fact that condoms do not offer full protection against many of the sexually transmitted infections caused by a virus. This authoritative passing-on of half the story comes from peer sex education.

Some of the girls interviewed had the maturity to confidently assert that "girls can just say no . . they have their rights". A macho male spoke about the guy going as far as he could with a girl. As soon as she said "no" he walked off and got someone else.

His casual attitude to using women and his ease in finding partners who allowed themselves be used painted a frightening picture.

Anyone who allows herself to be treated as a sex object lacks self-esteem. Guys also feel they have to protect themselves from predatory females. "Some girls would tell a fellow that they were on the Pill, but the guy wouldn't have sex without a condom."

These are revolutionary changes that have occurred in the behaviour of young women, who often initiate sex.

Young men have always experienced peer pressure to affirm their male identity by having sex. It came as no surprise to hear a lad say: "Guys my age score as many as you can. Friendship with girls is not really important."

This is a common belief among younger teenagers of both sexes. Thankfully, the unhealthy repressive attitudes of the recent past have gone. Unfortunately, they have been replaced with equally unhealthy liberal attitudes.

Peer influences to separate sex from love are hard to resist. When young people are asked what percentage of their friends are sexually active, they come up with figures between 60 and 90 per cent. Studies show that the actual figures are much lower. For older teenagers in education it is 32 per cent, and a little higher for early school-leavers.

Pat Kenny's more mature guests said how horrible it was to be slagged and asked: "Are you going to be a nun? Are you going to be a virgin all your life?" Another teen said all her friends had sex when they felt ready. She claimed she didn't feel influenced by friends who said "I had sex with this person or that person."

Blame the irresponsible behaviour of teenagers today on ignorance and lack of adult guidance. That widely accepted teenage belief that you know when you are ready for sex is as dangerous as the concept that parents, not schools, should give sex education.

RANDY TEENAGERS, who haven't the maturity to differentiate between love and lust, will always feel ready. Teenage magazines give advice like "It's up to you who you sleep with, just so long as you feel ready and use contraception . . . Before you have sex with anyone, make sure you know them." (from November issue of Sugar). This concept of teenagers having anonymous sex is both shocking and frightening.

Parents who are unaware of the dangers cannot pass on essential information. Many suspect that adolescent children are sexually active but cannot bring themselves to talk about using contraception, the implications of a possible pregnancy or the danger of contracting a sexually transmitted infection.

Silence greeted a Late Late panellist, Dr Derek Friedman, when he mentioned a foreign study of sexually active teenagers that found a 25 per cent incidence of chlamydia among sexually active 13- to 15-year-olds. The mean time for re-infection was six months.

Unless the belief that it is okay to have sex when it feels right is challenged, this is the nightmare scenario that may lie ahead for sexually active adolescents, who are not taught about the risks.