The film takes place in three bathrooms. Two of them are side-by-side and the third sees the two right across the street. In these 3 places, 3 different couples and a young voyeur boy (actually an art student who researches for a project) are described in stories. At the core of these stories there are determinations of the nature of men and women, marriage and betrayal.
A wife accidentally locks herself in with a guy in the bathroom, which leads to them fucking on the bathroom floor (34:31). It's non-nude but we see the wife's tit in the bathtub earlier (18:50). Her husband, brandishing a gun, breaks down the door later and a confrontation ensues.