In Santiago, Chile, the schoolteacher Luisa proposes a debate about sex with the parents of her students with the intention of giving classes about sex education to the youngsters. She is a young independent woman that is split between the love for her young mate, the painter ValentÑn, and for her experienced lover, the middle-age father of one of her students and successful writer Jorge. Jorge still lives with his wife Mónica, but their marriage ended and they do not even talk to each other, but his affair with Luisa is limited to sex and he doesn't seem to want a serious relationship. In the meeting, the parents are divided in groups, and Luisa stays with Jorge, and the couples womanizer Álvaro and his pregnant wife Elena and shy butcher Emilio and his frigid wife Maca. Álvaro is a wolf man, harasses all the beautiful women that he meets for one night stand, unfaithful and neglecting his wife at home. When Luisa finds that she is pregnant and Valentin is going to work in São Paulo, s