Nijinsky (movie, 1980)

The film suggests Nijinsky was driven into madness by both his consuming ambition and self-enforced heterosexuality, the latter prompted by his romantic involvement with Romola de Pulszky, a society girl who joins impresario Sergei Diaghilev's Ballets Russes specifically to seduce Nijinsky. After a series of misunderstandings with Diaghilev, who is both his domineering mentor and possessive lover, Nijinsky succumbs to Romola's charms and marries her, after which his gradual decline from artistic moodiness to complete lunacy begins.