A major theme is prostitution.
There is one scene in which old men are seen having sex with much younger women. Brief images of nudity and sex in a motel room where prostitutes are having sex; we see quick male full frontal and rear nudity, a brief shot of a couple having intercourse as they are interrupted, another couple having sex standing in a shower and then being interrupted, and we also see brief female topless and rear nudity (no genitalia). The scene is shaky, energetic, and quickly edited - played for shock/bizarre comedy. Lots of the content listed above will fly right by most viewers if they are not expecting the scene.
A blow-job is shown in a carwash from behind in a car with no nudity nor audio (brief).
A man masturbates in a car while a prostitute holds his scrotum (no nudity), he stops when he realizes it isn't working; played for comedy.
A man pulls down a prostitutes shirt to briefly reveal her breasts, and then pulls open her pants, revealing partial frontal nudity, he stops when he realizes she is not transgender.
Frank, graphic, and sometimes comedic descriptions of sexual references, transactions, and propositions.
Most of the sexual content is based on the story's plot and dialogue; little nudity is actually seen on-screen.