If you know a movie that isn't on this list, email me the title below.

The Ballad of Jack and Rose (2005)

https://www.imdb.com/title/tt0357110/ 
A beautifully told story of a daughter loving a father who is afraid to admit that love. The actress is beautiful and brilliantly acted.

The Ballad of Jack and Rose, 2005

Ma mère (2004)

https://www.imdb.com/title/tt0381392/
Mom corrupted her son. Then he gets jealous of his girlfriend. Everything ended sadly: the young man masturbates on the corpse of his beloved mother.

Ma mère

Aki Sora (2009), Aki Sora: Yume no Naka (2010)

https://www.imdb.com/title/tt12150068/ and https://www.imdb.com/title/tt3953656/?ref_=nm_flmg_t_23_ardp 
Two sisters, a brother, a classmate. Four people and two sexual lines. Interestingly, there was not a single scene in which the genitals were visible.

Aki Sora

Savage Grace (2007)

https://www.imdb.com/title/tt0379976/
The film is based on real events. I read about this slkuchay, it seems, on Wikipedia. A murky story. I was curious about how you can make a movie about incest with Julian Moore. The film is bullshit and an attempt to catch a hype on the topic of incest.Savage Grace

Eugénie (1973)

https://www.imdb.com/title/tt0218181/
After the death of the mother, the stepfather and stepdaughter enter into an intimate relationship because of love. But the worst thing is that Dad is dragging his daughter into murder. What a horror. The film is not very good, by modern standards. But a novel in this scenario can be made good.

Eugenie 1973