"You Lost Me" is a song by American singer Christina Aguilera, from her 2010 album "Bionic". The song was written by Aguilera, Samuel Dixon and Sia Furler. It's a slow melody pop-ballad song that talks about a cheating boyfriend, who has left the world in Aguilera's view as "infected". It was released on July 6, 2010 as the third single from Aguilera's "Bionic" album.