The Cement Garden (1992)

One of seven films adapted from Ian McEwan's novels, Andrew Birkin's 1993 The Cement Garden presents a darkly disturbing look at the lives of four siblings who bury their mother in the basement before engaging in incestual relationships and cross-dressing in the rooms above.

After dad has a heart attack and illness slowly kills their mother, siblings Julie, Jack, Tom and Sue are left to fend for themselves. Worried that they will be split up and taken into care, they encase their mother in cement under the house. They don't tell anyone that she has died and live off her bank account.
Sixteen-year-old Julie carries out her mother's dying wish and acts as mum to her sister and two brothers.

However, the children undergo huge changes: mutual attraction draws Julie and Jack together into a sexual relationship, Tom struggles with his sexuality, and Sue withdraws silently into her journal.

The film offers a dark, yet fascinating, look at sexual behaviour in a house where authority and social checks are removed. And, it seems that the brothers and sisters could live out their own 'norm' forever, until Julie invites back a date who is not only shocked by her relationship with her brother, but becomes transfixed with what is buried the cellar...