Britney's "If U Seek Amy".
The surface meaning is Britney, being the darling and sweetheart that she is, searching for a lost soul named Amy at what is presumed to be a college sorority party. Britney searches the bathroom and outside the club where Amy is known to frequent during her many smoke trips but to no avail. She even asks persons in the vicinity what Amy was wearing and what state she was in before she disappeared. Sadly, the song never reveals whether or not Amy was found - quite a tragic ballad, if you ask me.
The secondary meaning is a lot more perverted and a lot less dramatic.
"You think your pain and your heartbreak are unprecedented in the history of the world, but then you read." - James Baldwin