Chetna (1970)

A shy and reclusive young man, Anil Dhawan, gets to meet a prostitute, Seema, through his friends, Ramesh. Anil is very shy at the very first meeting with Seema, and then starts to cultivate a friendship with her. She responds also, and both fall in love. Anil proposes marriage, and Seema is delighted to accept. Anil has to go out of town for a four or five days. When he returns, he finds Seema has taken up drinking alcohol and smoking in a big way, and appears despondent, and non-chalant, making him wonder what had happened during his absence to make her regress in this manner.