Teenagers must be taught about oral and anal sex, according to experts who have found that young people are taking part in a wider range of sex acts than they were 20 years ago.
Researchers investigating the sex habits of those aged between 16 and 24-years-old discovered that the number who have had vaginal, oral and anal sex in the past year has risen from one in ten women and men between 1990 and 1991, to a quarter of men and one in five women between 2010 and 2012 who have been sexually active in the past year.
While vaginal intercourse and oral sex are the most common combination of sexual practices that young people have taken part in, the biggest spike was seen in the number of 16 to 18-year-olds who have had oral and anal sex.
The teams at the London School of Hygiene and Tropical Medicine and UCL behind the study published in the 'Journal of Adolescent Health' made their findings by analysing data from the National Surveys of Sexual Attitudes and Lifestyles (Natsal). To date, over 45,000 people have taken part in the studies carried out every 10 years since 1990, making them the largest scientific probes into sexual health and lifestyles ever in the UK.
The research is the latest to suggest that sex education must be drastically updated to better equip young people.
Dr Ruth Lewis, the lead author of the study who was based at the London School of Hygiene & Tropical Medicine, said it is "crucial" that students are taught about current trends in sexual practices.
"This will equip young people with the information and skills they need to maximise their well- being from the outset of their sexual lives," she said.
Kaye Wellings, senior author and Professor of Sexual and Reproductive Health at the London School of Hygiene & Tropical Medicine, said: "The changes in practices we see here are consistent with the widening of other aspects of young people's sexual experience, and are perhaps not surprising given the rapidly changing social context and the ever-increasing number of influences on sexual behaviour.
"It is important to keep up to date with trends in sexual lifestyles to help young people safeguard their health and increase their well being".
The study sheds light on the acts that young people engage in outside of sexual intercourse. For instance, it found that the average age that young people have their first heterosexual experience hasn't changed, remaining at 14 for behaviour such as kissing and 16 for intercourse.
Prior studies at involving LSHTM have suggested that young girls are more likely to perform oral sex on their partner, even if they don't want to; and are also coerced into having anal sex.
In a piece for IBTimes UK, Stephanie Alys, co-founder of sex toy firm MysteryVibe, has argued that young people need to be educated about how to safely use products including vibrators.
This article has been amended to make it clear that the figures refer to young people who have said they were sexually active in the past year, rather than all young people.