Le Frisson des Vampires

Le Frisson des Vampires English title The Shiver of the Vampires is a 1971 film directed by Jean Rollin. It is his third vampire movie.

Isle goes to the cemetery to visit the graves of her cousins, and a woman named Isabelle tells Isle that she was about to get married to both of her cousins, but in a way she was already their brides. Isle decides to sleep alone on that night because she is upset. While getting ready for bed a woman emerges from the grandfather clock. She introduces herself as Isolde and takes Isle back to the cemetery where she bites Isle in the neck. Antoine, feeling lonely, goes to see Isle, but she isnt in her room. He searches the castle and comes to the chapel where it seems a human sacrifice is taking place. Two of the participants turn out to be Isles cousins and explain they must kill the woman or she will become like them vampires. Antoine goes back to find Isle in her room and isnt sure whether it was all a dream.The next morning at breakfast the Renfields tell Isle and Antoine that her cousins arent really dead. Antoine goes to the library to meet the cousins but is instead knocked out by books. When he comes to, Antoine goes back to the dining room where he finally meets the cousins. That night Isle decided to sleep alone again, leaving Antoine angry. Isolde returns to Isle and bites her in the neck again. Isabelle tells a friend that Isles cousins were once vampire slayers and were bitten by vampires. Isabelle later discovers that the cousins are still alive and under Isoldes control and Isolde tells her she is no longer welcome at the castle. She grabs Isabelle and pierces her breasts with her pointed nipple covers. Angry at her for doing this the cousins rape Isolde. ........

Source: Wikipedia