The original French title is slang for "balls" (the testicular variety).
The scene with Gérard Depardieu, Patrick Dewaere and Miou-Miou in bed together was considered shocking for 1974 audiences. Depardieu would have a similar scene only a few years later co-starring with Robert De Niro and Stefania Casini in Novecento (1976).
In an interview, Miou-Miou said that she kept from this film "a very powerful memory, very collective, with Dewaere and Depardieu. We were sometimes asked to do things that were not hard, but a little complicated to do. By dint of pulling down my panties and pulling up my apron, I was getting a little tired of it. The three of us loved each other very much. We were like a litter of puppies."
In reference to the scene on the train Brigitte Fossey said, "I was supposed to breastfeed a child but I had no milk. I then smeared my breasts with honey and the baby saw nothing but fire".
Isabelle Huppert was 21 when she shot this movie although her character, Jacqueline, is said to be 16.