During one lengthy segment of un-simulated consensual sadomasochism, a fully nude woman's butt is visible. Between her spread legs, her vulva is visible with enough detail to discern labia. Pain is inflicted. See details below.
During another lengthy segment of un-simulated consensual BDSM, a fully nude man's scrotum is visible. His penis is visible; in some scenes flaccid, in another extended scene it is erect and twitching. Sexual hand-to-genital contact is seen. Pain is inflicted; this segment is intense. See details below.
Other scenes include additional full male and female nudity, frank and detailed discussions of sexual activity, and visually unappealing (and perhaps unusual; I don't know) submissive/dominant pseudo-sexual behavior. See details below.
Nudity: male full rear and frontal nudity; female rear and topless nudity.