A teenager's expectations of relationships today bear no resemblance to what was expected 25 or 30 years ago. This is a fact that is frequently ignored and needs to be addressed by teachers who take responsibility for the implementation of relationship and sexuality education (RSE) programmes.

There are many teachers who grew up in an era when contraception was not readily available. People were terrified of unmarried pregnancy and fear dampened sexual desires. Frightened adolescents learned to repress their natural sexual feelings and, even as adults, some are still uncomfortable about sex.

Some of these teachers have no concept of the sexual pressure faced by young people today. They still assume that control in a relationship is as simple as a girl saying "no".

In the recent past, the majority of couples saved sex for marriage. However, it is naive of teachers to suggest they did so because of higher moral standards. Men were seldom socially penalised when they made a girl pregnant, but the girl was stigmatised. She was ostracised socially and an unmarried pregnancy could ruin a young woman's life and bring disgrace on her extended family.

That is the main reason why, historically, sex was saved for marriage. Fewer than 30 years ago, traditional roles for men and women were supported by government departments and other large firms: women were forced to resign their jobs on marriage. Students today are horrified when they learn of the sexist attitudes that made women financially dependent on men.

In the traditional model of marriage, the expectations of a caring husband was that he became the breadwinner and showed his love by going out to work and bringing in money to support the material needs of his family. A good wife stayed at home to cook his meals, look after their home and care for their children.

Sexual equality and improved educational opportunities have changed attitudes and expectations of relationships. Today, women anticipate that they will provide for their own material needs. Few have any desire to be financially dependent on a man.

Economic freedom has radically changed the role of women and altered their expectations of relationships with men. Some no longer view marriage as a desirable option. They expect to have their emotional needs met in committed, non-permanent, long-term serial partnerships.

Teachers need to acknowledge this change and help pupils explore their understanding of marriage. Parents who are unhappily married influence their childrens' decisions about marriage.

Students have moved beyond the traditional roles expected of men and women. Some RSE teachers have not. They hold out-of-date views about couple relationships, and fail to show any understanding of the social changes that have occurred in family relationships. Schools are failing students when they ignore how sexual behaviour and adolescents' expectations of relationships have changed.

Many teenagers dine alone and feel isolated in busy families. They seek to meet their emotional needs in sexual relationships. Sexually active students expose themselves to serious health risks that no other generation faced. Few families talk about these issues.

In many single-parent families, and two-parent families when both parents are working outside the home, there is little adult supervision. Fertility control and paid part-time employment gives teenagers sexual freedom and a financial independence enjoyed by no previous generation.

Teachers who are not sensitively aware of the changed expectations students have of intimate relationships are unlikely to be able to help them understand how peer pressure and wrong attitudes influence premature sexual behaviour.

RSE is more personally challenging than other areas of education because the beliefs and values a teacher holds impact on what is being taught. For example, a young teacher living with a partner may believe that her principal would disapprove of her lifestyle; consequently, in the classroom she will talk as if she is opposed to sex before marriage.

A conservative teacher who is fearful of offending cohabiting parents may adopt a pseudo-liberal approach, but fail to conceal the disapproval she really feels. Students are fine-tuned to pick up these contradictions.

RSE programmes should create a safe and trusting atmosphere where students can communicate honestly and learn how to deal with sexual pressure. The question that schools need to address is: will programmes be effective when pupils find that teachers are out of touch or see them modelling dishonest.

Carmel Wynne teaches RSE in primary and post-primary schools.