The producers also thought it would be interesting for there to be more to Shannon and Boone's relationship than just Boone's possessive brotherly interest.[6] According to Cuse, the plot twist had become a Lost characteristic so they wanted to surprise the audience by having the Shannon-Boone relationship be sexual in nature. The idea for the two came from an observation that their bickering resembled an older married couple; to support this, they made the characters step-siblings as it had not yet been established what their sibling bond exactly was.[2]