Tunnel (1980)

Tunnel, also known as Eroina, is a 1980 Italian film (released in 1983) directed by Massimo Pirri. The story follows Marco and Pina (Corinne Clery), two chronic drug addicts trapped in the spiral of heroin addiction. To support their need, they live by expedients, frequenting environments of crime and degradation, populated by thieves and prostitutes, until a dramatic denouement.
In the 18th minute Corinne Clery lifts her skirt to get a shot on her pussy. It is rather creepy, but watching the scene is less disturbing than it may seem. In the 24th minute Agnès Nobecourt gets out of bed totally naked and walks to the bathroom, followed by a man. Moments later she is putting her clothes on and talking to the man, who is sitting on the couch. In the fifty-eighth minute Corinne Clery has sex with a man on a bed. The actress is dressed, but the man lifts her skirt revealing her thighs and ass.