Anoche soñé contigo / Dreaming About You (1992)

It's summer break, so Toto (Altomaro) and Quique (Mora) can dream their life away by biking around their neighbourhood and spying on Quique's maid, Chabelita (Aguirre). When Toto's young and attractive cousin Azucena (Perdigon) arrives to spend some days in Toto's home the kid is attracted to her immediately. What Toto doesn't know is that her visit will bring him an experience he would never forget.

Imdb