The Man in the Moon (1991)

Maureen Trant and her younger sibling Dani share a strong connection but local boy Court Foster threatens to throw their bond off balance Dani and Court meet first and have a flirtatious rapport but when he meets Maureen he falls hard and they begin a passionate affair The new couple try to keep their love hidden from Dani but she soon learns the truth disavowing her sister But a heartbreaking accident later reunites the girls