Sharada(1957)

After Shekhar (Raj Kapoor) falls for beautiful Sharada (Meena Kumari), he makes her promise that she'll wait for him while he goes abroad on a business trip. But when Shekhar's plane goes down in flames, Sharada finds comfort in the arms of another man, not knowing that he's Shekhar's widowed father (Raj Mehra). Trouble is, Shekhar survived the crash and soon returns home, only to discover that Sharada has become … his mother!