Le Souffle au Coeur/Murmur of the Heart(directed by Louis Malle),1971.Someone else asked about this one, but with a different description,though both are correct.It's about the sexual explorations of a young teenage lad,including an element of incest with his mother at ahealth spa.Extremely enjoyable.Try the same director's excellent,but certainly more serious,Au Revoir les Enfants.