Arnold Schonberg's Pierrot Lunaire

A young girl that regularly dresses as a boy falls in love and seduces a young girl that has no clue that her lover has the same sex. When the girl introduces 'her boyfriend' to her father he becomes skeptical and unmasks the fraud. Even though, strangely, the feelings of the girl persist without shifting, the father does not allow them to ever see the other again. Furious and delusional the 'boy' develops an adventurous plan to prove his true 'masculinity' to the father of his lover.