Actually, the title 'Sexperiencias' has nothing to do with sex: it comes from the double plurality of 'experience' (one front and one behind S).
The economic conditions in which Nunes was forced to work were so precarious that 'Sexperiencias' was filmed with expired celluloid film.
Since the film had never been approved by Francoist censorship due to his leftist political content, 'Sexperiencias' was conceived and distributed clandestinely and by hand.