It's pretty obvious what the "big dipper" is in this song, but we'll tell you anyway: It's a penis.
The song is campy fun, telling the story of a guy whose partner has found another "big dipper," leading him to play the field and find some more stars of his own.
It's the first overtly gay song Elton John released; he admitted he was bisexual in a 1976 Rolling Stone
interview, and quickly learned that some people didn't respect his lifestyle choice. This song is a nod to his homosexuality without openly discussing it. In 1981, Elton released a more sincere gay love story in "Elton's Song