Just for funsies I've been browsing my way through Television Tropes lately (that site has a lot to answer for) and I came across two words that chilled me to my core: Relationship Sue. The site defines this term as: 'A Mary Sue who exists to be the perfect mate for a specific character [...] The author will generally either use this character as a stand-in for them to vicariously live out a relationship with the designated other half [...] They don't really become a Relationship Sue unless it becomes obvious that character exists, first and foremost, to be in a relationship with another character.' That made me nervous because in my novel I have a character whose sole purpose is to be the MC's love interest. The romantic subplot is important because it acts as a catalyst for certain events in the main plot, however the character herself has never really been of great interest to me, other than to make her into the sort of charater my MC would fall in love with. She is essentially a plot device, and quite propbably fits the definition of a 'relationship sue'. My question is: is that a bad thing? Should I go back and try to give her some secondary purpose, or is it ok that I've created a character purely for my MC to fall in love with her? Does anyone else have characters like this? Or can you think of any examples of other stories that do?