There is only one sex scene between Lizzie and Brian. At the beginning both strip their clothes and kiss passionately. Then a man thrusts vigorously against Lizzie. Lizzie moans loudly. However Lizzie's bra is still on. No genitals are visible. Eventually the man stops the act and Lizzie begins to masturbate herself. No obvious nudity is shown.
Lizzie appears in a bathroom scene standing at the sink. When she turns around, the robe that she has on is untied and you can see that she is nude underneath. She then ties her robe. It's just brief nudity.
Brief full frontal female nudity and graphic female masturbation.
A scene where a robe gapes very quickly displays little nudity due to poor lighting and distance, on a large UHD TV you can vaguely make out what appears to be some pubic hair but is in no way graphic and no nipples etc are visible.