* AdaptationDisplacement: The movie is based on Gilbert Adair's ''The Holy Innocents'', a British novel so obscure that it has received only one hardcover and print back release. It only got a reprint in conjunction with the release of the film.
* BestKnownForTheFanservice: If anyone remembers this film, it's because of the fact that it was the film debut of Creator/EvaGreen who spends most of the runtime either engaged in sexual acts, undressing or just baring it all. In fact, the movie helped establish her reputation as a MsFanservice.
* FauxSymbolism: During the loss of [[spoiler: Isabelle]]'s virginity Theo cracks an egg, symbolizing the loss of innocence. Since the egg joins two others in a frying pan, it may also symbolize Matthew's induction into a serious relationship with the twins.
* QuestionableCasting: Isabelle and Theo are supposed to be twins, but Eva Green and Louis Garrel, who respectively portray them, look nothing alike. Though for what it's worth it does tone down the squick factor a little bit.
* SpiritualSuccessor: To ''Film/LesEnfantsTerribles'', which also has an unconventional brother/sister relationship at its core, as well as a man who gets involved with the sister.
* {{Squick}}: BrotherSisterIncest is just the ''start''.