In Jess Franco's Love Letters of a Portuguese Nun (1977) [German: Die Liebesbriefe einer portugesischen Nonne], after Father Vicente, a middle-aged priest and The Confessor of Sins, catches 15-year-old Maria (Susan Hemingway) committing "... wicked and shameful behavior." in the woods with a 17-year-old boy, the priest convinces Maria's mother to send the nymphet to the convent. Father Vicente warns that Maria, "... will surely be condemned to hell if she continues to run loose."
Upon arriving at the convent, Maria is
After the nymphet passed her vaginal exam, she was sent to the confessional. Father Vicente inquired, "Did you ever experience pleasure?" Maria answered by describing how she performed oral sex on her older cousin in a dream. Father Vicente audibly masturbated until orgasm during Maria's confession.
Maria is then shown to her room and is soon visited by the two youngest nuns in the convent. One of the young nuns welcomes Maria with a "sisterly kiss" on the lips before the nuns invite Marie to play a lesbian "game". But their game is interrupted by the Grand Priestess who, on the orders of Father Vicente, proceeds to sensually undress Maria and wrap her nude body in thorns. The Grand Priestess informs Maria that she must endure the pain of the thorns to achieve salvation.
When a letter that Maria sends her to mother explaining the hypocrisy of Father Vicente is intercepted, Maria is placed in a "cell of isolation" to repent; however, Father Vicente informs Maria that if she really wants to repent she must make, "A holy sacrifice," by sacrificing her virginity to Satan (Herbert Fux). But before Marie has the honor of sacrificing her virginity, she must prove herself worthy of the "honor" by performing a task or "penance", which is to perform oral sex on Father Vicente! Subsequently, Maria's 15-year-old virginity is taken by the Devil in the midst of the nuns masturbating and having lesbian sex.
In the end, Maria refuses to believe that it was all a dream and does everything that she can to escape the convent, expose Father Vicente and Mother Alma, and avoid being burned at the stake.
Interestingly, Susan Hemingway was 14-years-old when Love Letters of a Portuguese Nun (1977) was filmed in Germany where the age-of-consent is, you guessed it, 14.