Really? Twincest should be the first reaction to the word "twins," except for people who aren't at all into incest. Emily would be pining for Katie and Katie would be totally oblivious, or on the contrary would know about it and tease her and Emily would be all sad. :-(

I'm glad I'm not the only one seeing Effy/Emily. ^_^ Effy/Katie and Naomi/Katie have been mentioned, but not Effy/Emily. Strange...