Aap Ki Kasam (1974)
(Released: May 3, 1974)
Rich and wealthy Sunita (Mumtaz) meets with a struggling middle-class young man, Kamal Bhatnagar (Rajesh Khanna) in her college, and both are attracted to each other. Kamal's dad (A.K. Hangal) and Sunita's parents (Dina Pathak, Rehman) approve of their relationship, and soon both are married. Life is blissful, until Mohan (Sanjeev Kumar) shows up in their lives and Kamal starts having doubts about Sunita's fidelity. These doubts boomerang out of control, resulting in the separation of the two, who still love each other in their hearts, but are unable to exorcise doubt and suspicions from their lives.