This horror movie stars Natasha Kinski and Malcolm McDowell. They are brother and sister and their secret is they turn into black leopards.
Natasha plays Irena and she comes back home to live with her brother (played by McDowell). Her brother tries to sexually advance on her because their family and ancestors had to have sex with each other otherwise they turn into black leopards forever unless they kill someone and only then will they transform back to human form. That’s only if they have sex with other people.
Irena falls in love with Oliver who works at the zoo and at the time is dating a coworker named Alice. Irena tells Alice one day that she’s a virgin and from then on Alice sees Irena as competition for Oliver. Irena ends up having sex with Oliver and ends up in her black leopard form and thus has to kill to return to her human form. I won’t give the ending up because it’s a sad ending with a twist.
Definitely check this movie out it has romance, sex, some violence, and taboo.