Dangerous Charm 1979

No one can ever forget their own past, and some people use it to hurt themselves.

Directed by Chana Kraprayoon

An emotionally unstable spinster still hasn't gotten over the fact that her sister married the man she loved years ago. When her niece brings a new boyfriend home, memories of the past drive her to the brink of madness and she starts resorting to vicious, violent behavior to ruin the relationship.