The plot revolves around a married high school teacher's affair with his 17-year-old student Mathilde. Concern is expressed that due to the teacher-student relationship she's under the age of consent, (18 in this circumstance rather than the usual 15).
Sex is stated to be ongoing. Events aren't shown but are implied: In several scenes people partly undress themself or others and then lie down together, or are shown afterwards in bed. Breasts and upper thigh/side of butt are seen for several seconds. One cut ends abruptly as Mathilde reaches inside her panties.
There's no male nudity. Views of kissing and touching hands are short.
We see brief views of breasts and butt during non-sexual activity.
There's some dialog about sex. Mathilde and her teacher talk about it mostly without vulgarity, also, a woman is said to have had many lovers. The verb "screw" is used.