Watch The Buttercup Chain (1970) Official Trailer

When two people are in love they're a couple. When four people are in love they're the Buttercup Chain.

Born to twin sisters on the same day in London, France and Margaret are more like brother and sister than cousins. The close relationship between the cousins is suspended when Margaret is sent abroad for schooling. Now a young woman, Margaret returns to London and resumes her intimate connection with France.