Sexuality education as appropriate are part of learning process of culture in each communities has been taken over by formal education as if communities doesn’t have its own ways to educate the youth about sexuality. Formal education its essence are to support communities to undergo changes of era apparently seem like create its own standards in sexuality. This study will show that formal education, especially in school, practically are still not notice the diversity of community’s cultures. Education in school are obscure diversity and created new value standard that not every communities will achieve and use it in everyday life.

This study use ethnographic method, especially in case of pregnant before marriage in youth’s life. The data collected from the stories and deep observations of phenomenon from a youth community in one marginal kampong in Yogyakarta after 4 years. From sex education in school, youth receive knowledge about reproduction system and moral values that follow it, what youth can do and what forbidden to do. They taught that intercourse can make someone pregnant. They also taught that pregnant should happen in a marriage bond. So, sexual activities are better to do after marriage

In their community, they receive sexuality not only as knowledge but also as experience. They saw what other members of community do sexual activities in romantic relation, and they don’t have to be marriage first. What they saw become their knowledge and then they do it when they have a romantic relationship.

When pregnant before marriage happens, most of the youth doesn’t know what to do. They don’t feel that they do the right thing from school sex education point of view. In the contrary, they just do what the community usually do in romantic relation. Value from school education are forbid to do sexual activities before marriage, but in their community that is normal thing to do. After pregnant happens, what they did are judge by their own community with values from school education.

What happened in the case of youth that experienced pregnant before marriage at least show that formal education from school are still not take values and experience in communities. They ignore that communities has its own ways to live their life, and give them the higher values, not an acculturated values. They obscure diversity in community culture.

In community now had a hierarchy in values. They do things base on their own values. When something that community think are wrong happens, they use another values that they think above their own values to judge what they have done. The values in community become resistant, not become productive values that can make cultural development. Furthermore, community will fail to develop their culture to undergo changes of era. A culture nation that are still try to build in Indonesia base on diversity communities culture will fail.