In Poland, formal marriage is a dominant form of living in a relationship. However, more and more often, the so called, alternative forms are applied, most notably cohabitation. Relationships of that type are based on long-term, intimate relationship of two people of opposite sex who live together, without being a formal married couple. A number of such relationships in Poland is growing systematically, and they are gaining increasing social acceptance. Also mass media have their contribution to popularization of living in a cohabitation. This paper shows results of my own research aimed at getting to know students’ opinions about cohabitation relationships. Moreover, presentation of persons living in informal relationships has been analysed based on the most popular TV series.