Side Show is a Broadway musical about Daisy and Violet Hilton, two Siamese Twins who make a change from being a circus side show act to becoming famous stage performers in the 1930s, even appearing in a couple of B-Grade movies. The show was written by Bill Russell and Henry Krieger and ran for 91 performances from 1997-1998. It was nominated in 1998 for four Tony Awards.
One unusual element of this play is that the two lead actresses must play their parts “joined at the hip.” It doesn't matter how good their individual talents are if they can't work together and do it convincingly. The success of the show depends on the success of their partnership. If one of them decides to go solo, the show is over! They're only in business as long as they stick together.
That is a good picture of marriage. Once the commitment is made, husband and wife are, as it were, “joined at the hip.” They succeed or fail together. Other people don't generally think of one without thinking of the other. Wherever life's drama takes them, their success lies in doing it together “until they are parted by death.”