That Cold Day in the Park (1969)

"How far will a woman go? How far will a 32 year-old spinster go to possess a strange, 19 year-old boy?"

Frances Austen, a young, wealthy spinster, invites a mute teenager into her apartment after finding him freezing in the park next to where she lives. Despite her best efforts, their lack of communication only increases her sense of loneliness, as her possessiveness spirals into frightening new realms.