Cat People (1982)

Irena Gallier suffers from a genetic curse that forever dooms her to turn her into a giant black panther every time she is kissed. If she is kissed twice, she turns back into a naked woman. If she is kissed thrice, she turns back into a black panther. If she is kissed four times in a row, the curse makes her permanently naked and the only way for her to regain the ability to wear clothing is to pass the curse on to another woman, preferably by kissing her on the lips and putting her tongue inside her -- ahem -- mouth.

Unfortunately, for Irena, she is very attractive to both men and women. Plus she really, really likes kissing.