It is the 20th century but believe it or not, ending a relationship because the parents doesn't approve of it still happens. Parents have various reason for disapproval--religion, family background, social status, looks, etc. Regardless of the reason, still many couples separate ways because one of the partners value and respect their parents and are afraid of being disowned by their own family.
I have a colleague who had an unplanned pregnancy with her boyfriend for years. Despite being in a relationship with the guy for years, her parents are still against their relationship. When she discovered they were pregnant, they eloped but eventually decided to face their parents to sort things out. At first, the parents were furious to the point of really disowning her. Fortunately, her parents finally accepted the fact that she is pregnant with the guy they despise and were married soon after.
Would you or would you not pursue a relationship your parents doesn't approve of?