Pelli Kanuka(1960)

Bhaskar (Akkineni Nageswara Rao) and Vasanti (B. Saroja Devi) are college mates who clash when she complains to the college principal about a love letter he sent her. Later on realizing her mistake, Vasanti apologizes to him and the two fall in love. Vasanti's elder sister, Geeta (Krishna Kumari), supports the family by stitching clothes.Bhaskar rents the room upstairs in their house. He falls ill and in nursing him, Geeta falls in love with him. She confides her love to Vasanti, who decides to sacrifice her love for her the sake of her sister and convinces Bhaskar to marry Geeta. Bhaskar initially neglects Geeta. On finding out, Vasanti writes to him that their sacrifice, made for Geeta's happiness, would mean nothing unless he is a good husband to Geeta. Bhaskar relents and Geeta and he have a son. Vasanti joins them and Geeta suspects that there is something on between Bhaskar and Vasanti and makes Vasanti leave the house.